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1

Alternative isotope enrichment processes  

SciTech Connect

Alternative processes such as gas centrifugation, plasma separation, and laser excited separation are evaluated for use at the ORNL Stable Isotope Enrichment Facility. The applicabiliy of each process to the isotopic enrichment of the calutron feed material and to the selective production of isotopes is determined. The process energy demands are compared to those of the existing facilities. The isotopic enrichment of the feed material prior to a first-pass through the calutrons can result in a significant saving in energy.

Terry, J.W.

1983-01-01

2

Advanced Uranium Enrichment Processes.  

National Technical Information Service (NTIS)

Three advanced Uranium enrichment processes are dealt with in the report: AVLIS (Atomic Vapour LASER Isotope Separation), MLIS (Molecular LASER Isotope Separation) and PSP (Plasma Separation Process). The description of the physical and technical features...

M. Clerc P. Plurien

1986-01-01

3

Categories of Processes Enriched in Final Coalgebras  

Microsoft Academic Search

Simulations between processes can be understood in terms of coalgebra homomorphisms, with homomorphisms to the final coalgebra exactly identifying bisimilar processes. The elements of the final coalgebra are thus natural representatives of bisimilarity classes, and a denotational semantics of processes can be developed in a final-coalgebra-enriched category where arrows are processes, canonically represented. In the present paper, we describe a

Sava Krstic; John Launchbury; Dusko Pavlovic

2001-01-01

4

Aerodynamic isotope separation processes for uranium enrichment: process requirements  

Microsoft Academic Search

The pressing need for enriched uranium to fuel nuclear power reactors, requiring that as many as ten large uranium isotope separation plants be built during the next twenty years, has inspired an increase of interest in isotope separation processes for uranium enrichment. Aerodynamic isotope separation processes have been prominently mentioned along with the gas centrifuge process and the laser isotope

Malling; G. F. Von Halle

1976-01-01

5

Evaluation of uranium-enrichment processes  

SciTech Connect

The purpose of this paper is to outline some of the methods used in evaluating uranium enrichment processes. The paper shows how one can choose among these many processes and what features are crucial in deciding between them. These features can be grouped into technical and economic factors. The technical factors include separation factor, throughput, inventory of material, and specific power requirement. The economic factors are: (1) capital cost of plant and supporting facilities; (2) operating costs including maintenance costs; and (3) power costs. Besides these essential factors, other factors may also need to be considered. These are: (1) potential for further process improvements; (2) reliability of the process equipment; (3) difficulty of manufacturing and handling the process medium; (4) process flexibility; (5) scaling factors; (6) social factors; (7) political factors. The paper illustrates how these basic technical and economic evaluation factors are applied to real enrichment methods. The gaseous diffusion process is used as a reference process and compared with the following processes: gas centrifuge; advanced isotope separation; thermal diffusion; fractional distillation; mass spectrograph; and mass diffusion. Another point that needs to be considered is that some evaluations of uranium enrichment processes change over a period of time because of advances in technology or changes in economic climate. (ATT)

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

1982-01-01

6

Process energy of the advanced chemical uranium enrichment process  

SciTech Connect

Process energy of the chemical uranium enrichment process is discussed using the dynamic enrichment factor, avoiding a cluster of commonly used equations that correlate relevant engineering parameters. An advanced process, whose process energy was found to be much smaller than in the original process in both laboratory and bench tests, has been recently developed and applied to a pilot plant. The basic principle underlying the improvement is an inverse redox reaction induced by the increased sorbability of multi-coordinated metal-complex ions onto an ion-exchange resin. The energy requirement for the advanced process will be reduced to <100 kW . h/kg . separative work unit.

Takeda, K.; Onitsuka, H.; Obanawa, H.; Saito, S. (Asahi Chemical Industry Co., Ltd., Uranium Enrichment Lab., 1-1 Takeshima, Hyuga-shi 883 (JP))

1988-06-01

7

Theoretical Consideration and Recent Progress of Chemical Enrichment Process for Uranium Enrichment  

Microsoft Academic Search

Research and development for uranium enrichment by oxidation-reduction chromatography, begun in 1972 despite the prevailing view that a chemical process would require several centuries of operation to attain fuel-grade uranium enrichment and would thus be impractical, led to the establishment of basic process technology permitting attainment of 3% enrichment within several months of operation by the mid 1980, through advance

Maomi SEKO; Kunihiko TAKEDA; Hatsuki ONITSUKA; Tetsuya MIYAKE

1990-01-01

8

Enrichment of xanthohumol in the brewing process.  

PubMed

Xanthohumol (XN), a component of hops, is lost in significant quantities in the conventional brewing process. In commercial beers less than 0.2 mg XN/L are found. In order to increase the yield of XN in the brewing process, the parameters of XN recovery were studied. During wort boiling, XN is largely isomerised to isoxanthohumol. Further losses are owing to the precipitation and absorption of XN to yeast cells and haze particles and by filtration. The use of XN-enriched hop products combined with a late hop dosage during wort boiling proved to be effective in increasing the XN content in beer. The yield was further raised by a low-pitching rate and the abnegation of beer stabilisation. The use of dark malts had a positive effect on the XN recovery. Investigations of roasted malt extracts revealed several high-molecular substances that are able to form complexes with XN. These complexes proved to be stable in the brewing process. Depending on the addition of roasted malt or special XN-enriched roasted malt extracts, dark beers with more than 10 mg XN/L were achieved. Results obtained led to a brewing technology that produced on an industrial scale pale wheat beer with more than 1 mg XN/L. PMID:16097021

Wunderlich, Sascha; Zürcher, Achim; Back, Werner

2005-09-01

9

Novel Membranes and Processes for Oxygen Enrichment  

SciTech Connect

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

Lin, Haiqing

2011-11-15

10

Process for enriching a population of sperm cells  

US Patent & Trademark Office Database

Processes for selectively enriching a population of viable sperm cells with respect to a characteristic without physically sorting the cells are disclosed. The cells contained in such an enriched population benefit from the advantage of not being subjected to a sorting process. Processes of inseminating a female mammal and processes of forming a sperm dispersion utilizing the processes of selectively enriching a population of viable sperm cells are also disclosed.

2010-11-16

11

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

12

Business Process and Risk Models Enrichment: Considerations for Business Intelligence  

Microsoft Academic Search

Business intelligence (BI) as a paradigm with methods and tools substantially improves decisions with regard to business evolutions. Through the emerging business process management approaches, it becomes possible to link BI-tools with the underlying process models. This paper explains how process models can be enriched with risk models in the context of business intelligence.

Amadou Sienou; Achim P. Karduck; Elyes Lamine; Hervé Pingaud

2008-01-01

13

Efficiency evaluation of oxygen enrichment in energy conversion processes  

SciTech Connect

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

Bomelburg, H.J.

1983-12-01

14

Interstellar Tin: Probing Galactic s- Process Elemental Enrichment  

NASA Astrophysics Data System (ADS)

We propose a study to obtain high quality interstellarabundance data for the heavy element Sn (Z = 50), an elementproduced mainly by s-process neutron capture in intermediate-to-low mass AGB stars, in a number of ISM sight lines knownto sample a range of gas densities and depletions onto dust.Current (limited) data on Sn/H in a few dense ISM sight linescharacteristic of large gas depletions onto dust show theabundance to be consistent with the solar value (i.e. nodepletion onto dust). However, since Sn should be chemicallysimilar to the other periodic table group IVA elements (i.e.C, Si, Ge, Sn, Pb) which share a common outer electron shellstructure and which are depleted from solar by at least afactor 3, it should be somewhat depleted onto dust.Consequently, we believe that the apparent solar abundancereflects the fact that the ISM ( cosmic) abundance of Sn hasincreased since the formation of the solar system 4.5 billionyears ago. This supposition is not unreasonable: observationsof other heavy s-process elements in the atmospheres of someintermediate-to-low mass AGB stars show substantialenrichments and so we expect that some heavy s-process elementenrichment of the ISM must have occurred. What makes thescience proposed here significant is that it provides a greatopportunity to determine the degree of enrichment, yieldingimportant information on bulk s-process yields and cumulativeinjection of this material into the ISM over the past

Meyer, David

1995-07-01

15

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

16

The VSA Process for Oxygen Enrichment: Process Description and Dynamic Modeling Using Neural Networks  

Microsoft Academic Search

Air separation for oxygen enrichment via the pressure\\/vacuum swing adsorption (PSA\\/VSA) process is an important unit operation in many large industrial processes. However, complexities associated with it being a bulk separation process operating in a cyclic, non-equilibrium, unsteady state manner presents significant difficulties in understanding the physics involved. Also, previous attempts in modeling the system numerically have resulted in complications

Chris C. K. Beh; Paul A. Webley; Kate A. Smith

2003-01-01

17

Autoxidation of oil emulsions during the Artemia enrichment process  

Microsoft Academic Search

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

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

1995-01-01

18

Equilibrium time and criticality considerations in uranium enrichment by the chemical-exchange process  

Microsoft Academic Search

The equilibrium time for production of enriched uranium and the effective neutron multiplication factor κ{sub eff} are calculated for ion-exchange uranium enrichment based on the U(IV)-U(VI) electron-exchange reaction process. Experimental data are shown to fit well with the calculated equilibrium time curve. It is concluded that under the assumed process operating conditions, as much as 10 yr would be required

Y. Fujii; M. Okamoto; H. Kadotani; H. Kakihana

1989-01-01

19

Uranium enrichment by the separation-nozzle process  

Microsoft Academic Search

The development of reliable manufacturing methods for commercial separation elements, the successful operation of separative stages, and extensive tests performed on plant components and auxiliary systems provide the basis for the construction of a separation-nozzle demonstration plant. The performance level achieved to date characterizes the process as reliable and economically feasible. In particular, it is generally ally accepted that comparatively

E. W. Becker; W. Bier; W. Ehrfeld; K. Schubert; R. Schütte; D. Seidel

1976-01-01

20

Some fuel cycle implications of metal-based uranium enrichment processes  

Microsoft Academic Search

Currently, all production-scale uranium enrichment processes require UFâ feed and supply UFâ product to the fuel fabricator. The industries for feed production from the ore concentrate and processing UFâ product to the required nuclear fuel UOâ are well established. Although technology for making and handling uranium metal has been utilized on a production scale for many years, significant changes in

J. N. Pashley; R. L. Smith; J. H. Thomas

1982-01-01

21

Magnetic separation as a plutonium residue enrichment process  

SciTech Connect

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

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

1989-01-01

22

Method for thermal processing alumina-enriched spinel single crystals  

DOEpatents

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

Jantzen, C.M.

1995-05-09

23

Uranium enrichment measurement by X- and ?-ray spectrometry with the “URADOS” process  

Microsoft Academic Search

The methods used for the uranium enrichment measurement require in general prior instrument calibration with several standards. Thus, it is possible to avoid the constraints involved in calibration by considering the complex spectral region called XK?. This spectral region is sufficiently limited so that the variation of the detector efficiency response is small enough to facilitate a self-calibration. Processing this

Jean Morel; Michel Etcheverry; Gilles Riazuelo

1998-01-01

24

Processes of mantle enrichment and magmatic differentiation in the eastern Snake River Plain: Th isotope evidence  

NASA Astrophysics Data System (ADS)

The ˜ 85 km long Great Rift of southern Idaho bisects the volcanic depression that forms the eastern Snake River Plain. Thorium isotope systematics of compositionally diverse lavas of the Great Rift, including those of Craters of the Moon, record a spectrum of crust and mantle processes. ( 230Th) /( 232Th) ratios range from 0.87 to 1.11 and are enriched in ( 230Th) with respect to ( 238U) by up to 13%. Covariations in Th isotope systematics in lavas from Craters of the Moon reflect crustal assimilation accompanied by fractional crstallization involving accessory phases. Temperatures based on apatite and zircon saturation confirm other estimates of magmatic temperatures and, considered together with volcanic histories, suggest cooling in upper crustal magma chambers at rates of > 10° C/ka. Thermal and chemical evolution of the Great Rift basalts support their differentiation at lower crustal conditions. Although basalts of the eastern Snake River Plain are generally interpreted as having originated in ancient enriched mantle lithosphere beneath southern Idaho, they share remarkable chemical similarities with oceanic basalts derived from enriched sources attributed to mantle plumes. Thorium isotope signatures of the Great Rift basalts are those of depleted mantle, resulting in the most extreme case of disparity between 232Th/238U ratios delimited by Th and Pb isotope systematics. It is difficult to account for this decoupling by invoking subduction-related U enrichment. A more likely explanation is metasomatism of hybrid lithospheric mantle in the wake of the Yellowstone plume.

Reid, Mary R.

1995-04-01

25

Process for producing dry, sulfur-free, CH[sub 4]-enriched synthesis or fuel gas  

Microsoft Academic Search

A process is described for the production of a dry, sulfur-free methane enriched synthesis gas or fuel gas stream comprising: (1) cooling a particulate-free raw synthesis or fuel gas feed stream comprising H[sub 2], CO, CO[sub 2], H[sub 2]O, N[sub 2], H[sub 2]S, COS and with or without methane to a temperature in the range of about 60 F to

E. T. Child; W. L. Jr. Lafferty; R. M. Suggitt; F. C. Jahnke

1993-01-01

26

Processes of mantle enrichment and magmatic differentiation in the eastern Snake River Plain: Th isotope evidence  

Microsoft Academic Search

The ? 85 km long Great Rift of southern Idaho bisects the volcanic depression that forms the eastern Snake River Plain. Thorium isotope systematics of compositionally diverse lavas of the Great Rift, including those of Craters of the Moon, record a spectrum of crust and mantle processes. (230Th)(232Th) ratios range from 0.87 to 1.11 and are enriched in (230Th) with

Mary R. Reid

1995-01-01

27

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

28

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

PubMed

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

Wasserburg; Qian

2000-01-20

29

Processing of low-burnup LEU (low enriched uranium) silicide targets  

SciTech Connect

Currently much of the world's supply of /sup 99m/Tc for medical purposes is produced from ZZMo derived from the fissioning of high enriched uranium (HEU). Substitution of low enriched uranium (LEU) silicide fuel for the HEU alloy and aluminide fuels used in current target designs will allow equivalent ZZMo yields with no change in target geometries. In these studies, targets were irradiated to low burnup (10/sup /minus/5/%) to produce fission products and STZNp at concentrations conveniently measured by gamma spectroscopy. Processing was done by dissolution of LEU targets in acid or base followed by alumina column recovery ZZMo. Acid dissolution is more rapid, but precipitation of silica results in loss of ZZMo. Dissolution of U3Si2--Al targets in base requires more processing steps than the current process for UAl/sub x/--Al fuel. A two-step process of first dissolving the 6061Al cladding and fuel meat aluminum, and then dissolving the U3Si2 fuel particles, has the advantage of eliminating the aluminum from further processing. Loss of ZZMo during the aluminum dissolution is attributed to recoil of ZZMo out of the silicide particles during irradiation. A larger particle size would decrease this ZZMo loss. 6 refs., 4 figs., 2 tabs.

Kwok, J.D.; Vandegrift, G.F.; Matos, J.E.

1988-09-01

30

Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants  

SciTech Connect

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

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

2010-01-01

31

Analysis of civilian processing programs in reduction of excess separated plutonium and high-enriched uranium  

SciTech Connect

The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. The analysis addresses several options in reducing the excess separated plutonium and HEU, and the consequences on nonproliferation and safeguards policy assessments resulting from the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials.

Persiani, P.J.

1995-12-31

32

Effects of processing conditions of the green-leafy vegetable juice enriched with selenium on its quality stability  

Microsoft Academic Search

The authors used selenium-enriched vegetables as test materials during research on juice production. The purpose of this study is to provide a basis for developing a practical processing technology. The changing regularity of two quality attributes on three Se-enriched green-leafy vegetable juices was studied during juice making. The effects of processing conditions on chlorophyll contents, total Se content and organic

Zhang Min; Li Chunli; Cao Ping

2004-01-01

33

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

SciTech Connect

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

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

2013-01-01

34

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

35

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

SciTech Connect

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

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

2008-02-01

36

Process for producing dry, sulfur-free, CH[sub 4]-enriched synthesis or fuel gas  

SciTech Connect

A process is described for the production of a dry, sulfur-free methane enriched synthesis gas or fuel gas stream comprising: (1) cooling a particulate-free raw synthesis or fuel gas feed stream comprising H[sub 2], CO, CO[sub 2], H[sub 2]O, N[sub 2], H[sub 2]S, COS and with or without methane to a temperature in the range of about 60 F to 130 F and separating out at least a portion of water condensate; (2) mixing together said cooled raw synthesis or fuel gas from (1) and a portion of cryogenic liquefied natural gas (LNG) thereby further cooling the new synthesis or fuel gas to a temperature in the range of about [minus]75 F to 60 F; (3) directly contacting the mixture from (2) in an acid-gas removal zone with liquid acid-gas absorbent solvent thereby absorbing sulfur-containing compounds, water, and at least a portion of the CO[sub 2], and thereby producing acid-gas rich liquid absorbent solvent containing dissolved water and a dry stream of methane enriched synthesis or fuel gas; (4) separating said acid-gas rich liquid absorbent from said dry stream of methane enriched synthesis or fuel gas comprising H[sub 2], CO, CH[sub 4], and substantially no sulfur-containing gas or moisture; (5) regenerating the separated acid-gas rich liquid absorbent solvent to remove the sulfur-containing gas and the dissolved water; and (6) introducing regenerated liquid acid-gas absorbent solvent into said acid gas removal zone.

Child, E.T.; Lafferty, W.L. Jr.; Suggitt, R.M.; Jahnke, F.C.

1993-08-03

37

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

Microsoft Academic Search

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

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

2008-01-01

38

Biomass of Spirulina maxima enriched by biosorption process as a new feed supplement for swine.  

PubMed

This paper deals with the new mineral feed additives with Cu produced in a biosorption process from a semi-technical scale. The natural biomass of edible microalga Spirulina sp. was enriched with Cu(II) and then used as a mineral supplement in feeding experiments on swine to assess its nutrition properties. A total of 24 piglets divided into two groups (control and experimental) were used to determine the bioavailability of a new generation of mineral feed additives based on Spirulina maxima. The control group was feed using traditional inorganic supplements of microelements, while the experimental group was fed with the feed containing the biomass of S. maxima enriched with Cu by biosorption. The apparent absorption was 30 % (P?

Saeid, A; Chojnacka, K; Korczy?ski, M; Korniewicz, D; Dobrza?ski, Z

2012-09-25

39

Sweeping as a multistep enrichment process in micellar electrokinetic chromatography: the retention factor gradient effect.  

PubMed

The application of a new method developed for the assessment of sweeping efficiency in MEKC under homogeneous and inhomogeneous electric field conditions is extended to the general case, in which the distribution coefficient and the electric conductivity of the analyte in the sample zone and in the separation compartment are varied. As test analytes p-hydroxybenzoates (parabens), benzamide and some aromatic amines are studied under MEKC conditions with SDS as anionic surfactant. We show that in the general case - in contrast to the classical description - the obtainable enrichment factor is not only dependent on the retention factor of the analyte in the sample zone but also dependent on the retention factor in the background electrolyte (BGE). It is shown that in the general case sweeping is inherently a multistep focusing process. We describe an additional focusing/defocusing step (the retention factor gradient effect, RFGE) quantitatively by extending the classical equation employed for the description of the sweeping process with an additional focusing/defocusing factor. The validity of this equation is demonstrated experimentally (and theoretically) under variation of the organic solvent content (in the sample and/or the BGE), the type of organic solvent (in the sample and/or the BGE), the electric conductivity (in the sample), the pH (in the sample), and the concentration of surfactant (in the BGE). It is shown that very high enrichment factors can be obtained, if the pH in the sample zone makes possible to convert the analyte into a charged species that has a high distribution coefficient with respect to an oppositely charged micellar phase, while the pH in the BGE enables separation of the neutral species under moderate retention factor conditions. PMID:23726349

El-Awady, Mohamed; Pyell, Ute

2013-05-02

40

Microbial response to a mesoscale iron enrichment in the NE subarctic Pacific: Heterotrophic bacterial processes  

NASA Astrophysics Data System (ADS)

The response of heterotrophic bacteria to an in situ mesoscale Fe-addition was characterized during the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), in the high nutrient low chlorophyll region of the Northeast subarctic Pacific, during July 2002. Samples were collected from inside and outside the Fe-enriched patch for the determination of bacterial biomass, and rates of production and growth, and community respiration. The addition of Fe significantly changed the dynamics of the mixed layer heterotrophic bacterial community compared to unfertilized waters. Outside the patch, bacterial dynamics remained relatively constant. Inside the Fe-enriched patch, depth-integrated bacterial biomass decreased 5-fold during the first 12 days after fertilization, after which biomass increased more than 10-fold, to a maximum of 23.3 mg C m-3. Similarly, bacterial production decreased 3-fold over the first 8 days, followed by a 15-fold increase to 5.7 mg C m-3 d-1. Bacterial specific growth rates remained constant for 8 days after the initial Fe-addition and close to values initially observed outside the patch. After day 8, mixed layer specific growth rates inside the patch increased more than 10-fold to a maximum of 1.24 d-1 by day 12, then steadily decreased to 0.22 d-1 by day 16 and remained relatively constant thereafter. Temporal changes in growth were not significantly different inside and outside the patch, suggesting that bacterial growth was not directly limited by Fe availability. The temporal uncoupling of bacterial biomass and production inside the patch, combined with the lack of evidence for direct iron limitation, suggest that inside the patch, bacteria were initially controlled by a combination of moderate bottom-up control, due to the effects of organic substrate limitation of bacterial growth, and strong top-down control, by processes such as microzooplankton bacterivory or viral lysis. Release of bacteria from grazing pressure (around day 12), coupled with an increase in specific growth rate (day 8), resulted in the rapid increase in bacterial biomass observed towards the end of the observation period. Mixed layer bacterial carbon demand ranged from 1.5 to 22.9 mg C m-3 inside the patch and accounted for an average (±st dev) of 25% (±11%) of primary production. Consequently, a high proportion of the Fe-enhanced primary production in the mixed layer during SERIES was channelled through the microbial food web, thus reducing the amount of organic carbon available for export.

Hale, Michelle S.; Rivkin, Richard B.; Matthews, Paul; Agawin, Nona S. R.; Li, William K. W.

2006-10-01

41

Microbial response to a mesoscale iron enrichment in the NE subarctic Pacific: Heterotrophic bacterial processes  

NASA Astrophysics Data System (ADS)

The response of heterotrophic bacteria to an in situ mesoscale Fe-addition was characterized during the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), in the high nutrient low chlorophyll region of the Northeast subarctic Pacific, during July 2002. Samples were collected from inside and outside the Fe-enriched patch for the determination of bacterial biomass, and rates of production and growth, and community respiration. The addition of Fe significantly changed the dynamics of the mixed layer heterotrophic bacterial community compared to unfertilized waters. Outside the patch, bacterial dynamics remained relatively constant. Inside the Fe-enriched patch, depth-integrated bacterial biomass decreased 5-fold during the first 12 days after fertilization, after which biomass increased more than 10-fold, to a maximum of 23.3 mg C m -3. Similarly, bacterial production decreased 3-fold over the first 8 days, followed by a 15-fold increase to 5.7 mg C m -3 d -1. Bacterial specific growth rates remained constant for 8 days after the initial Fe-addition and close to values initially observed outside the patch. After day 8, mixed layer specific growth rates inside the patch increased more than 10-fold to a maximum of 1.24 d -1 by day 12, then steadily decreased to 0.22 d -1 by day 16 and remained relatively constant thereafter. Temporal changes in growth were not significantly different inside and outside the patch, suggesting that bacterial growth was not directly limited by Fe availability. The temporal uncoupling of bacterial biomass and production inside the patch, combined with the lack of evidence for direct iron limitation, suggest that inside the patch, bacteria were initially controlled by a combination of moderate bottom-up control, due to the effects of organic substrate limitation of bacterial growth, and strong top-down control, by processes such as microzooplankton bacterivory or viral lysis. Release of bacteria from grazing pressure (around day 12), coupled with an increase in specific growth rate (day 8), resulted in the rapid increase in bacterial biomass observed towards the end of the observation period. Mixed layer bacterial carbon demand ranged from 1.5 to 22.9 mg C m -3 inside the patch and accounted for an average (±st dev) of 25% (±11%) of primary production. Consequently, a high proportion of the Fe-enhanced primary production in the mixed layer during SERIES was channelled through the microbial food web, thus reducing the amount of organic carbon available for export.

Hale, Michelle S.; Rivkin, Richard B.; Matthews, Paul; Agawin, Nona S. R.; Li, William K. W.

2006-10-01

42

Enrichment of anammox from activated sludge and its application in the CANON process.  

PubMed

A microbial culture capable of actively oxidizing ammonium to dinitrogen gas in the absence of oxygen, using nitrite as the electron acceptor, was enriched from local activated sludge (Western Australia) in <14 weeks. The maximum anaerobic ammonium oxidation (i.e., anammox) activity achieved by the anaerobic culture was 0.26 mmol NH (4) (+) (g biomass)(-1) h(-1) (0.58 kg total-N m(-3) day(-1)). Qualitative FISH analysis (fluorescence in situ hybridization) confirmed the phylogenetic position of the enriched microorganism as belonging to the order Planctomycetales, in which all currently identified anammox strains fall. Preliminary FISH analysis suggests the anammox strain belongs to the same phylogenetic group as the Candidatus 'Brocadia anammoxidans' strain discovered in the Netherlands. However, there are quite a few differences in the target sites for the more specific probes of these organisms and it is therefore likely to represent a new species of anammox bacteria. A small amount of aerobic ammonium-oxidizing biomass was inoculated into the anammox reactor (10% v/v) to initiate completely autotrophic nitrogen removal over nitrite (the CANON process) in chemostat culture. The culture was always under oxygen limitation and no organic carbon was added. The CANON reactor was operated as an intermittently aerated system with 20 min aerobiosis and 30 min anaerobiosis, during which aerobic and anaerobic ammonium oxidation were performed in sequential fashion, respectively. Anammox was not inhibited by repeated intermittent exposure to oxygen, allowing sustained, completely autotrophic ammonium removal (0.08 kg N m(-3) day(-1)) for an extended period of time. PMID:15735941

Third, K A; Paxman, J; Schmid, M; Strous, M; Jetten, M S M; Cord-Ruwisch, R

2005-02-24

43

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

44

Marriage and Family Enrichment: A Process Whose Time has Come (and Gone?)  

ERIC Educational Resources Information Center

Reviews enrichment research of the 1990s. Examines marriage preparation and premarital counseling; specific programs, such as Training in Marriage Enrichment; specific populations, such as children; and continuing research needs, particularly in the areas of measurement, participants, and program characteristics. Claims that marriage and family…

Giblin, Paul

1996-01-01

45

Processing and kinetics studies on the alumina enrichment of coal fly ash by fractionating silicon dioxide as nano particles  

Microsoft Academic Search

Coal fly ash produced in the northern China is a potential bauxite substitute for aluminum production because of its high alumina content. However, this industrial application has been limited for its high silicon content. Alumina enrichment by removing silicon becomes a key technology for its utilization. A novel process was developed to fractionate the coal fly ash into high purity

Guanghui Bai; Wei Teng; Xianggang Wang; Hui Zhang; Peng Xu

2010-01-01

46

A hybrid process combining oxygen enriched air combustion and membrane separation for post-combustion carbon dioxide capture  

Microsoft Academic Search

For carbon dioxide capture and storage (CCS), similar to a large majority of industrial processes, the separation (i.e. capture) step dominates the costs of the technological chain. Based on a concept of minimal work of concentration, the evaluation of a tentative capture framework which combines an oxygen enrichment step before combustion and a CO2 capture step from flue gas has

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

47

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

48

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

SciTech Connect

A separation means and method are described for enriching a hydrogen atmosphere with at least one heavy hydrogen isotope by using a solid titanium alloy hydride. To this end, the titanium alloy hydride containing at least one metal selected from the group consisting of vanadium, chromium, manganese, molybdenum, iron, cobalt and nickel is contacted with a circulating gaseous flow of hydrogen containing at least one heavy hydrogen isotope at a temperature in the range of -20/sup 0/ to +40/sup 0/C and at a pressure above the dissociation pressure of the hydrided alloy selectively to concentrate at least one of the isotopes of hydrogen in the hydrided metal alloy. The contacting is continued until equilibrium is reached, and then the gaseous flow is isolated while the temperature and pressure of the enriched hydride remain undisturbed selectively to isolate the hydride. Thereafter, the enriched hydrogen is selectively recovered in accordance with the separation factor (S.F.) of the alloy hydride employed.

Tanaka, J.; Reilly, J.J. Jr.

1978-02-21

49

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

ERIC Educational Resources Information Center

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

Memmert, Daniel

2006-01-01

50

Effects of Separation Processes on Minor Uranium Isotopes in Enrichment Cascades  

Microsoft Academic Search

In natural uranium, there are trace amounts of the “minor isotope” U in addition to the more abundant U and U. Uranium irradiated in a reactor and separated from the spent reactor fuel by reprocessing will contain additional minor isotopes. In uranium enrichment, cascades of separating units are tuned to produce the desired level of the isotope U, but the

HOUSTON G. WOOD

2008-01-01

51

Process for enrichment of a ferronickel alloy to 90 Pct Ni  

Microsoft Academic Search

The nickel of most lateritic ores is extracted as a FeNi alloy containing a certain amount of cobalt. The utilization of this\\u000a ferroalloy is effectively limited to the fabrication of stainless steels, which absorbs about 40 pct of the total nickel consumption.\\u000a The production of electrolytic nickel from ferronickel is feasible, but it requires anodes made of alloy enriched to

L. Moussoulos

1976-01-01

52

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

PubMed

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

Gohlke, O; Busch, M

53

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

54

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

55

Full-scale demonstration of the cintichem process for the production of Mo-99 using a low-enriched target.  

SciTech Connect

The irradiation, disassembly, and processing of two full-scale low-enriched uranium (LEU) targets were recently demonstrated by personnel in the BATAN PUSPIPTEK Facilities (Serpong, Indonesia). Targets were fabricated at Argonne National Laboratory (Argonne, IL, U.S.A.) and shipped to PUSPIPTEK. The processing was done by nearly the same procedure used for the production of {sup 99}Mo from high-enriched uranium (HEU) targets. The BATAN Radioisotope Production Centre produces {sup 99}Mo using the Cintichem process by first dissolving the uranium in an acid cocktail; three proprietary separation steps recover the {sup 99}Mo and purify it from other components of the irradiated uranium. Processing of LEU-metal targets is nearly identical to that used for HEU-oxide targets except (1) a separate dissolver is required and (2) the dissolution cocktail is nitric acid alone rather than a nitric/sulfuric acid mixture. The demonstrations went smoothly except for problems with sampling and gamma analysis to assess product purity. Foils could be removed from targets fabricated from zirconium and/or 304 stainless steel, and processing produced an equivalent yield of {sup 99}Mo/{sup 235}U to that of the HEU target.

Mutalib, A.

1998-10-28

56

How to cope with your sulfur problems. [COPE process; use of oxygen enriched air to increase capacity  

SciTech Connect

COPE (Claus Oxygen-based Process Expansion) technology presents an improvement to the modified Claus process that replaces air with up to 100% oxygen to debottleneck Claus Sulphur Recovery Unit's (SRU's). The major equipment requirements of the COPE process are the installation of an acid gas recycle blower and a proprietary burner. The recycle stream acts as a coolant to moderate reaction furnace temperature, effectively replacing nitrogen as a diluent. The specially designed burner allows for the safe and effective handling of the four feed streams: air, oxygen, acid gas, and recycle gas. Co-licensed by Goar, Arrington and Associates, Inc. (GAA) and Air Products and Chemicals, Inc., the COPE process presents an economically attractive means of expanding the capacity of an SRU. The first two COPE units are in commercial operation at a major gulf Coast refinery in the USA and have demonstrated an 85% increase in capacity by enriching to the 55% O/sub 2/ level.

Goar, B.G.; Hegarty, W.P.; Thew, T.W.

1986-01-01

57

Protein pathway biomarker analysis of human cancer reveals requirement for upfront cellular-enrichment processing.  

PubMed

Tissues are complex structures composed of different cell types, each of which present specific functions and characteristics. To better understand and measure the effect of tumor cell enrichment on protein pathway profiling and drug target activation measurements, the signaling activation portraits of laser capture microdissected (LCM) cancer epithelium and tumor stroma were compared with patient-matched whole-tissue specimens from 53 primary colorectal cancer samples. Microdissected material and whole-tissue lysate from contiguous cryostat sections were subjected to reverse-phase protein microarray analysis to determine the level of phopshorylation and expression of 75 different proteins known to be involved in cancer progression. The results revealed distinct differences in the protein activation portraits of cancer epithelium and stroma. Moreover, we found that the signaling activation profiles of the undissected whole-tissue specimens are profoundly different from the matched LCM material. Attempts to rescale the undissected pathway information based on percent endogenous tumor epithelium content were unsuccessful in recapitulating the LCM tumor epithelial signatures. Analysis of epidermal growth factor receptor phosphorylation and COX2 expression in these same sample sets revealed wholesale differences in the rank ordering of patient determination when LCM was compared with undissected samples. On the basis of these data, we conclude that accurate protein pathway activation status, which is under evaluation as a basis for patient selection and stratification for personalized therapy, must include upfront cellular-enrichment techniques such as LCM to generate accurate drug target activation status. PMID:20195244

Silvestri, Alessandra; Colombatti, Alfonso; Calvert, Valerie S; Deng, Jianghong; Mammano, Enzo; Belluco, Claudio; De Marchi, Francesco; Nitti, Donato; Liotta, Lance A; Petricoin, Emanuel F; Pierobon, Mariaelena

2010-03-01

58

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

SciTech Connect

As part of the U.S. nonproliferation effort, we are investigating the conversion of the production of fission-product {sup 99}Mo from use of high-enriched uranium (HEU) to low-enriched uranium (LEU). Successful conversion from HEU to LEU (<20% {sup 235}U) requires an irradiation target that contains 5 times more uranium but minimizes changes to target geometry and processing. The LEU target being developed uses thin foils of uranium metal that can be removed from the target hardware for dissolution and processing. This paper describes our recent successes in target fabrication, irradiation, and processing. Target fabrication has been improved by (1) heat-treating the uranium foil to produce a random, small-grain structure and (2) electrodepositing zinc and nickel fission-fragment barriers onto the foil. These fission-fragment barriers have been found to be stable during transport of the targets following irradiation. Recent irradiation tests have shown that the concept is sound. Progress was also made in broadening international cooperation in our development activities.

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

2000-01-01

59

Investigation of processes leading to nitrate enrichment in soils in the Kalahari Region, Botswana  

NASA Astrophysics Data System (ADS)

In Southern Africa elevated nitrate concentrations are observed in mostly uninhabited semi-arid areas. In the Kalahari of Botswana groundwater locally exhibits concentrations up to 600 mg/l. It is assumed, that nitrate found in the groundwater originates mainly from nitrogen input and transformations in the soils. Our investigations in the Kalahari between Serowe and Orapa show that cattle raising is an important source for enhanced nitrate concentrations in the soils (Arenosols). But also in termite mounds very high nitrate stocks were found, and under natural vegetation (acacia trees and shrubs) nitrate concentrations were mostly unexpectedly high. This nitrate enrichment in the soils poses a serious threat to the groundwater quality. However, calculated soil water age distributions in the unsaturated zone clearly show that today’s nitrate pollution of the groundwater below the investigation area could originate from natural sources, but cannot be caused by the current land use for cattle raising.

Schwiede, M.; Duijnisveld, W. H. M.; Böttcher, J.

60

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

2013-08-13

61

Preparation of a crosslinked bioimprinted lipase for enrichment of polyunsaturated fatty acids from fish processing waste.  

PubMed

Geotrichum sp. lipase modified with a combined method composed of crosslinking and bioimprinting was employed to selectively hydrolyze waste fish oil for enrichment of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in glycerides. Crosslinked polymerization by monomer (polyethylene glycol 400 dimethyl acrylate), crosslinker (trimethylolpropane trimethylacrylate), and photoinitiator (benzoin methyl ether) coupled to bioimprinting using palmitic acid as imprint molecule, resulted in much more effective enzyme preparation used in aqueous hydrolysis reaction. Since the crosslinked polymerization modification maintained bioimprinted property and gave good dispersion of enzyme in reaction mixture, the crosslinked bioimprinted enzyme exhibited higher hydrolysis temperature, enhanced specific activity, shorter hydrolysis time, and better operational stability compared to free lipase. Crude fish oil was treated at 45 degrees C with this crosslinked bioimprinted lipase for 8 h, and 46% hydrolysis degree resulted in the production of glycerides containing 41% of EPA and DHA (EPA+DHA), achieving 85.7% recovery of initial EPA and DHA. The results suggested that bioimprinted enzymes did not lose their induced property in aqueous environment when prepared according to the described crosslinking-bioimprinting method. It could also be seen that the crosslinked bioimprinted lipase was effective in producing glycerides that contained a higher concentration of polyunsaturated fatty acid with better yield. PMID:20101527

Yan, Jinyong; Li, Lifan; Tang, Qianli; Jiang, Manzhou; Jiang, Shenzhou

2010-01-26

62

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

Microsoft Academic Search

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

Juanita Martin Moore

2001-01-01

63

$sup 18$O enrichment process in UO$sub 2$F$sub 2$ utilizing laser light  

DOEpatents

Photochemical reaction induced by laser light is employed to separate oxygen isotopes. A solution containing UO$sub 2$F$sub 2$, HF, H$sub 2$O and a large excess of CH$sub 3$OH is irradiated with laser light of appropriate wavelength to differentially excite the UO$sub 2$$sup 2+$ ions containing $sup 16$O atoms and cause a reaction to proceed in accordance with the reaction 2 UO$sub 2$F$sub 2$ + CH$sub 3$OH + 4 HF $Yields$ 2 UF$sub 4$ down arrow + HCOOH + 3 H$sub 2$O. Irradiation is discontinued when about 10 percent of the UO$sub 2$F$sub 2$ has reacted, the UF$sub 4$ is filtered from the reaction mixture and the residual CH$sub 3$OH and HF plus the product HCOOH and H$sub 2$O are distilled away from the UO$sub 2$F$sub 2$ which is thereby enriched in the $sup 18$O isotope, or the solution containing the UO$sub 2$F$sub 2$ may be photochemically processed again to provide further enrichment in the $sup 18$O isotope.

DePoorter, G.L.; Rofer-DePoorter, C.K.

1975-12-01

64

Development of LEU (low enriched uranium) targets for sup 99 Mo production and their chemical processing status, 1989  

SciTech Connect

Most of the world's supply of {sup 99m}Tc for medical purposes is currently produced from {sup 99}Mo derived from the fissioning of high enriched uranium (HEU). Substitution of low enriched uranium (LEU) silicide fuel for the HEU alloy and aluminide fuels used in current target designs will allow equivalent {sup 99}Mo yields with no change in target geometries. Substitution of uranium metal for uranium oxide films in other target designs will also allow the substitution of LEU for HEU. Efforts performed in 1989 focused on (1) fabrication of a uranium metal target by Hot Isostatic Pressing uranium metal foil to zirconium, (2) experimental investigation of the dissolution step for U{sub 3}Si{sub 2} targets, allowing us to present a conceptual design for the dissolution process and equipment, and (3) investigation of the procedures used to reclaim irradiation uranium from Mo-production targets, allowing us to further analyze the waste and by-product problems associated with the substitution of LEU for HEU. 18 refs., 6 figs., 1 tab.

Vandegrift, G.F.; Kwok, J.D.; Chamberlain, D.B.; Hoh, J.C.; Streets, E.W.; Vogler, S.; Thresh, H.R.; Domagala, R.F.; Wiencek, T.C.; Matos, J.E.

1989-01-01

65

Processes involved in sweeping under inhomogeneous electric field conditions as sample enrichment procedure in micellar electrokinetic chromatography.  

PubMed

Sweeping under inhomogeneous electric field conditions has been described as a process that includes stacking or destacking of the micelles when entering the sample zone, sweeping of analytes by the stacked or destacked micelles, and destacking or stacking of the swept analyte zone. However, there is ongoing debate that not only the retention factor of the analyte but also the electric conductivity of the sample solution or the concentration of an added salt can have an impact on the enrichment efficiency. Revisiting the equations describing sweeping, a factor ? (phase ratio shift factor) is defined to quantitatively describe the change of the retention factor between the sample and separation zones. The influence of the sample matrix composition on the experimentally obtained sweeping efficiency is studied with SDS as pseudostationary phase taking parabens, benzamide and anilines as model analytes. To this end, a robust and reliable method for the assessment of the sweeping efficiency is developed. The values obtained via this method are very precise and agree well with theoretically predicted ones. The results obtained for varied buffer concentration and varied concentration of NaCl in the sample solution show that under the conditions of our experimental study, the approximation of assuming ? to be equal to the reciprocal value of the field strength enhancement factor ? is valid. Accordingly, the sweeping efficiency for neutral analytes is independent of the electric conductivity of the sample matrix. It is also shown that under specific conditions unexpectedly high enrichment factors are obtained which are ascribed to the focusing of neutral analytes by micellar transient isotachophoresis (mtITP). The results obtained in this study can be used as a guide for better understanding of the sweeping process and the factors affecting the sweeping efficiency in micellar electrokinetic chromatography (MEKC). PMID:23062880

El-Awady, Mohamed; Huhn, Carolin; Pyell, Ute

2012-09-23

66

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

67

AN INCREMENTAL LOADING PROCESS TO CONTROL PLUTONIUM ENRICHMENT IN MECHANICALLY-MIXED OXIDE FUEL SYSTEMS  

Microsoft Academic Search

Data and information concerning the distribution of PuOâ in UO\\/sub ; 2\\/ in mechanically mixed oxide fuel fabrications are presented. The areas of ; concern in control of Pu distribution include control of the absolute Pu content ; and control of the Pu longitudinal variation in each rod. Discussions are ; presented concerning vibratory and swage compaction processes in which

C. H. Bloomster; R. E. Bardsley; W. T. Ross

1962-01-01

68

Integration of biohydrogen fermentation and gas separation processes to recover and enrich hydrogen  

Microsoft Academic Search

An integrated system for biohydrogen production and separation was designed, constructed and operated where biohydrogen was fermented by Thermococcus litoralis, a heterotrophic archaebacterium, and a two-step gas separation process was coupled to recover and concentrate hydrogen. A special liquid seal system was built to deliver, compress and collect the laboratory scale, low volume gas mixtures consisting of hydrogen, nitrogen and

K. Bélafi-Bakó; D. Búcsú; Z. Pientka; B. Bálint; Z. Herbel; K. L. Kovács; M. Wessling

2006-01-01

69

NUCLEAR SAFETY IN THE UNIRRADIATED PROCESSING PHASES OF ENRICHED URANIUM FUEL CYCLES  

Microsoft Academic Search

Strict limitations must be imposed on the design and operation of ; industrial facilities processing fissionable material in order to prevent ; accidental nuclear chain reactions. Freedom from such criticality hazards can be ; attained by a program of nuclear safety incorporating geometric, administrative, ; and operational controls. This paper discusses briefly the fundamental nuclear ; safety methods common to

J. D. McLendon; J. W. Wachter; H. F. Henry

1958-01-01

70

Enrichment of Anammox bacteria in seed sludges from different wastewater treating processes and start-up of Anammox process  

Microsoft Academic Search

Three seed sludges (sludge A, B and C) were collected from various wastewater treatment processes. Then they were inoculated in Reactor A, B and C in parallel. After 67days of operation, only Reactor A successfully started up the Anaerobic ammonia oxidation (Anammox) process, while the other two reactors failed. The Anammox activity was observed within 49days and a final nitrogen

Tao Wang; Hanmin Zhang; Dawen Gao; Fenglin Yang; Shuai Yang; Tao Jiang; Guangyi Zhang

2011-01-01

71

Associative and inferential processes in pragmatic enrichment: The case of emergent properties  

Microsoft Academic Search

Experimental research on word processing has generally focused on properties that are associated to a concept in long-term memory (e.g., basketball—round). The present study addresses a related issue: the accessibility of “emergent properties” or conceptual properties that have to be inferred in a given context (e.g., basketball—floats). This investigation sheds light on a current debate in cognitive pragmatics about the

Paula Rubio-Fernández

2012-01-01

72

Palmitoleic Acid Enrichment of Seabuckthorn (Hippophaë rhamnoides L.) Pulp Oil by Crystallization Process  

Microsoft Academic Search

Seabuckthorn pulp oil was fractionated using a crystallization process with acetone under controlled cooling rate of 0.25°C\\/min without agitation at different crystallization temperatures ranging from ? 15 to 15°C. The obtained liquid (LF) and solid (SF) fractions were analyzed for their fatty acid and triacylglycerol compositions and their melting profiles were characterized. Fractionation at ? 15°C yielded about 20% of LF where palmitoleic acid

Luis-Felipe Gutiérrez; Khaled Belkacemi

2008-01-01

73

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

74

A Laboratory Model of a Prebiotic, Spontaneous, and Continuous Enantiomeric Enrichment Process  

NASA Astrophysics Data System (ADS)

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.

Goldberg, Stanley I.

2013-02-01

75

Uranium enrichment  

SciTech Connect

GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government.

Not Available

1989-01-01

76

Effect of processing and cooking on phenolic acid profile and antioxidant capacity of durum wheat pasta enriched with debranning fractions of wheat  

Microsoft Academic Search

The effect of processing and cooking on phenolic acids profile and antioxidant properties of durum wheat (Triticum turgidum L. var. durum) pasta samples enriched with debranning fractions of an Italian wheat (Triticum aestivum L.) cultivar were studied.Trolox equivalent antioxidant capacity (TEAC) by free radical scavenging activity against ABTS+ cation radical, phenolic acid profile, total phenolic content (TPC) and fibre were

Clara Fares; Cristiano Platani; Antonietta Baiano; Valeria Menga

2010-01-01

77

BLENDING LOW ENRICHED URANIUM WITH DEPLETED URANIUM TO CREATE A SOURCE MATERIAL ORE THAT CAN BE PROCESSED FOR THE RECOVERY OF YELLOWCAKE AT A CONVENTIONAL URANIUM MILL  

Microsoft Academic Search

Throughout the United States Department of Energy (DOE) complex, there are a number of streams of low enriched uranium (LEU) that contain various trace contaminants. These surplus nuclear materials require processing in order to meet commercial fuel cycle specifications. To date, they have not been designated as waste for disposal at the DOE's Nevada Test Site (NTS). Currently, with no

Stephen M. Schutt; Ron F. Hochstein; David C. Frydenlund; Anthony J. Thompson

2003-01-01

78

Alkaline peroxide processing of low-enriched uranium targets for {sup 99}Mo production -- Decomposition of hydrogen peroxide  

SciTech Connect

The recent progress on the alkaline peroxide processing of low-enriched uranium targets for the production of {sup 99}Mo, a parent nuclide of the widely used medical isotope {sup 99m}Tc, is reported. Kinetic studies were undertaken to investigate the decomposition of hydrogen peroxide in alkaline solution in contact with a uranium metal surface. It was found that the decomposition of hydrogen peroxide essentially follows the kinetic trend of uranium dissolution and can be classified into two regimes, depending on the hydroxide concentration. In the low-base regime (<0.2 M), both the hydrogen peroxide and hydroxide concentrations affect the rate of peroxide decomposition. In the high-base regime (>0.2 M), the rate of peroxide decomposition is independent of alkali concentration. When the acid/base equilibrium between H{sub 2}O{sub 2} and O{sub 2}H{sup {minus}} is taken into account, the overall rate of hydrogen peroxide disappearance can be described as a 0.25th order reaction with respect to hydrogen peroxide concentration over NaOH concentrations ranging from 0.01 to 5 M. Empirical kinetics models are proposed and discussed.

Dong, D. [Owens Corning Science and Technology Center, Granville, OH (United States); Vandegrift, G.F. [Argonne National Lab., IL (United States). Chemical Technology Div.

1997-06-01

79

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

80

Literature Review on Production Process To Obtain Extra Virgin Olive Oil Enriched in Bioactive Compounds. Potential Use of Byproducts as Alternative Sources of Polyphenols.  

PubMed

This review describes the olive oil production process to obtain extra virgin olive oil (EVOO) enriched in polyphenol and byproducts generated as sources of antioxidants. EVOO is obtained exclusively by mechanical and physical processes including collecting, washing, and crushing of olives, malaxation of olive paste, centrifugation, storage, and filtration. The effect of each step is discussed to minimize losses of polyphenols from large quantities of wastes. Phenolic compounds including phenolic acids, alcohols, secoiridoids, lignans, and flavonoids are characterized in olive oil mill wastewater, olive pomace, storage byproducts, and filter cake. Different industrial pilot plant processes are developed to recover phenolic compounds from olive oil byproducts with antioxidant and bioactive properties. The technological information compiled in this review will help olive oil producers to improve EVOO quality and establish new processes to obtain valuable extracts enriched in polyphenols from byproducts with food ingredient applications. PMID:23656613

Frankel, Edwin; Bakhouche, Abdelhakim; Lozano-Sánchez, Jesús; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2013-05-20

81

Enrichment, concentration and retention processes in relation to anchovy (Engraulis ringens) eggs and larvae distributions in the northern Humboldt upwelling ecosystem  

NASA Astrophysics Data System (ADS)

A Lagrangian model is used to simulate and quantify in the northern Humboldt upwelling ecosystem the processes of enrichment, concentration and retention, identified by Bakun [Bakun, A., 1996. Patterns in the ocean. Ocean processes and marine population dynamics. University of California Sea Grant, California, USA, in cooperation with Centro de Investigaciones Biologicas de Noroeste, La Paz, Baja California Sur, Mexico, 323 pp.] as being important for the survival and recruitment of early life stages of pelagic fish. The method relies on tracking the positions of particles within water velocity fields generated by a three-dimensional hydrodynamic model. Simple criteria for considering particles as participating to enrichment, concentration or retention are used to derive indices of the three processes. We analyse the spatial distribution of and seasonal variability in these indices. The results are discussed in relation to anchovy (Engraulis ringens) eggs and larvae distributions off Peru, and to a comparable study conducted in the southern Benguela upwelling ecosystem.

Lett, Christophe; Penven, Pierrick; Ayón, Patricia; Fréon, Pierre

2007-01-01

82

Uranium enrichment: technology, economics, capacity  

Microsoft Academic Search

Large-scale enrichment of uranium has now been carried out for 40 years. While the gaseous diffusion process was the original choice of several countries and continues today to provide the major component of the world production of separative work, the last two decades have witnessed the development of a number of alternative processes for enrichment. These processes, which are being

W. R. Jr. Voigt; P. R. Vanstrum; D. E. Saire; D. K. Gestson; S. E. Peske

1982-01-01

83

Profile of World Uranium Enrichment Programs-2009  

Microsoft Academic Search

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

Laughter; Mark D

2009-01-01

84

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

85

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

86

Job Enrichment  

ERIC Educational Resources Information Center

Job enrichment means giving people more decision-making power, more responsibility, more grasp of the totality of the job, and a sense of their own importance in the company. This article presents evidence of the successful working of this approach (Donnelly Mirrors), and the lack of success with an opposing approach (General Motors). (NL)

Sanders, Rick

1970-01-01

87

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

88

Improving classroom practice through curriculum enrichment  

Microsoft Academic Search

In this study I have researched the curriculum enrichment process. By enriching the curriculum I mean enhancing, deepening, improving and developing not only the syllabus but also other phases of curriculum objectives, like the teaching methodology, and the development of resources. Enriching the curriculum is a never-ending process; during the process I reflected critically on the implementation of the curriculum.

Saltanat Nasim

2003-01-01

89

Phytoplankton processes during a mesoscale iron enrichment in the NE subarctic Pacific: Part III—Primary productivity  

NASA Astrophysics Data System (ADS)

As part of the Canadian SOLAS program, a large scale iron (Fe) enrichment experiment (Subarctic Ecosystem Response to Iron Enrichment Study; SERIES) was performed in the NE subarctic Pacific in July of 2002. Dissolved Fe was added to a 77 km2 patch of seawater and the evolution of the subsequent phytoplankton bloom was monitored for 26 days. Particulate organic primary productivity (OPP) inside the patch began to increase in all phytoplankton size-fractions (picophytoplankton, nanophytoplankton and microphytoplankton) relative to outside the patch within 48 h. After day 10, microphytoplankton (>20 ?m) were responsible for the vast majority of both OPP and phytoplankton biomass. Maximum OPP of ca. 15 mmol C m-3 d-1 was achieved on day 15, representing a 20-fold increase from average OPP measured outside the patch. Water-column integrated, biomass (chl a)-specific OPP (Pbint) of the total phytoplankton assemblage peaked twice, once following the first Fe infusion on day 4 (2.9 mmol C mg chl a-1 d-1) and then coinciding with maximum OPP on day 15 (2.6 mmol C mg chl a-1 d-1). Maximum Pbint achieved on day 4 represented a 5-fold increase relative to Pbint measured outside the patch. Water-column integrated OPP also peaked on day 15 at ca. 251 mmol C m-2 d-1, and coincided with a rapid decline in silicic acid (Si(OH4)) concentrations. At this time, microphytoplankton accounted for ca. 90% of total OPP. Patch-averaged chlorophyll a (chl a) concentrations were maximal (˜5 mg m-3, >16 times the outside patch) on day 18, during which time microphytoplankton OPP had begun to decline. In addition to OPP, particulate inorganic primary productivity (IPP) also increased due to an elevated coccolithophore abundance, reaching a maximum of 0.25 mmol C m-3 d-1 achieved 9 days after the initial Fe enrichment, which then decreased back to rates similar to those measured outside of the patch. Changes in primary productivity were also assessed using pulse amplitude-modulated (PAM) fluorometry. Relative electron transport rates (ETR) obtained by PAM fluorometry were significantly correlated (p<0.001, r2=0.82) with the 14C-based primary production rates during the Fe enrichment experiment. The increase in all measured photosynthetic parameters with Fe enrichment provides compelling evidence that primary productivity in the NE subarctic Pacific is regulated by Fe availability during the summer.

Marchetti, Adrian; Sherry, Nelson D.; Juneau, Philippe; Strzepek, Robert F.; Harrison, Paul J.

2006-10-01

90

Phytoplankton processes during a mesoscale iron enrichment in the NE subarctic Pacific: Part III—Primary productivity  

NASA Astrophysics Data System (ADS)

As part of the Canadian SOLAS program, a large scale iron (Fe) enrichment experiment (Subarctic Ecosystem Response to Iron Enrichment Study; SERIES) was performed in the NE subarctic Pacific in July of 2002. Dissolved Fe was added to a 77 km 2 patch of seawater and the evolution of the subsequent phytoplankton bloom was monitored for 26 days. Particulate organic primary productivity (OPP) inside the patch began to increase in all phytoplankton size-fractions (picophytoplankton, nanophytoplankton and microphytoplankton) relative to outside the patch within 48 h. After day 10, microphytoplankton (>20 ?m) were responsible for the vast majority of both OPP and phytoplankton biomass. Maximum OPP of ca. 15 mmol C m -3 d -1 was achieved on day 15, representing a 20-fold increase from average OPP measured outside the patch. Water-column integrated, biomass (chl a)-specific OPP ( Pbint) of the total phytoplankton assemblage peaked twice, once following the first Fe infusion on day 4 (2.9 mmol C mg chl a-1 d -1) and then coinciding with maximum OPP on day 15 (2.6 mmol C mg chl a-1 d -1). Maximum Pbint achieved on day 4 represented a 5-fold increase relative to Pbint measured outside the patch. Water-column integrated OPP also peaked on day 15 at ca. 251 mmol C m -2 d -1, and coincided with a rapid decline in silicic acid (Si(OH 4)) concentrations. At this time, microphytoplankton accounted for ca. 90% of total OPP. Patch-averaged chlorophyll a (chl a) concentrations were maximal (˜5 mg m -3, >16 times the outside patch) on day 18, during which time microphytoplankton OPP had begun to decline. In addition to OPP, particulate inorganic primary productivity (IPP) also increased due to an elevated coccolithophore abundance, reaching a maximum of 0.25 mmol C m -3 d -1 achieved 9 days after the initial Fe enrichment, which then decreased back to rates similar to those measured outside of the patch. Changes in primary productivity were also assessed using pulse amplitude-modulated (PAM) fluorometry. Relative electron transport rates (ETR) obtained by PAM fluorometry were significantly correlated ( p<0.001, r2=0.82) with the 14C-based primary production rates during the Fe enrichment experiment. The increase in all measured photosynthetic parameters with Fe enrichment provides compelling evidence that primary productivity in the NE subarctic Pacific is regulated by Fe availability during the summer.

Marchetti, Adrian; Sherry, Nelson D.; Juneau, Philippe; Strzepek, Robert F.; Harrison, Paul J.

2006-10-01

91

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

PubMed Central

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

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

2013-01-01

92

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

2008-01-01

93

Phytoplankton processes during a mesoscale iron enrichment in the NE subarctic Pacific: Part I—Biomass and assemblage  

NASA Astrophysics Data System (ADS)

We report results from the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES) experiment in waters of the NE subarctic Pacific in which a large scale iron (Fe) enrichment lead to a shift in the phytoplankton assemblage from pico- and nanophytoplankton to one dominated by large diatoms. The phytoplankton response to the added Fe was monitored for 26 days following two infusions into a 77 km2 patch of seawater. During the course of the experiment, the resulting algal bloom was constrained within the upper 30 m and spread to a region measuring over 1000 km2. Phytoplankton chlorophyll a (chl a) increased from 0.3 mg m-3 to a peak of 6.3 mg m-3 18 days after the initial addition of Fe. Water-column integrated chl a was enhanced 8-fold, reaching a maximum of 114 mg m-2 on day 17. The resulting bloom is described in two ecological phases based on dominant phytoplankton groups. In Phase I, which encompassed the initial infusion up to day 10, all size-fractions (0.2 2, 2 20 and >20 ?m) increased in biomass as indicated by chl a, contributing to a surface standing stock of 2 mg m-3. In Phase II, from days 10 to 18, the bloom was dominated by microphytoplankton (>20 ?m), with a concomitant decrease in phytoplankton <20 ?m. Microphytoplankton, which initially accounted for 25% of the phytoplankton biomass and increased by a factor of 50, consisted primarily of the pennate diatom genera, Pseudo-nitzschia, Neodenticula and Thalassiothrix and the centric diatom genera, Chaetoceros, Rhizosolenia, and Proboscia. Particulate carbon-to-chl a (PC: chl a) ratios for large cells (?5 ?m) decreased 5-fold by day 18, indicative of enhanced cellular chl a content and increased phytoplankton contributions to PC. Pennate diatoms were most abundant in the patch, although when converted to biovolume, centric diatoms contributed larger amounts of algal carbon (C) to the bloom. A rapid decline in chl a on day 19 marked the onset of bloom decline. The magnitude, duration and composition of the phytoplankton response to the Fe enrichment clearly depicted a major shift in the structure of the algal assemblage and increased C export potential.

Marchetti, Adrian; Sherry, Nelson D.; Kiyosawa, Hiroshi; Tsuda, Atsushi; Harrison, Paul J.

2006-10-01

94

Phytoplankton processes during a mesoscale iron enrichment in the NE subarctic Pacific: Part I—Biomass and assemblage  

NASA Astrophysics Data System (ADS)

We report results from the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES) experiment in waters of the NE subarctic Pacific in which a large scale iron (Fe) enrichment lead to a shift in the phytoplankton assemblage from pico- and nanophytoplankton to one dominated by large diatoms. The phytoplankton response to the added Fe was monitored for 26 days following two infusions into a 77 km 2 patch of seawater. During the course of the experiment, the resulting algal bloom was constrained within the upper 30 m and spread to a region measuring over 1000 km 2. Phytoplankton chlorophyll a (chl a) increased from 0.3 mg m -3 to a peak of 6.3 mg m -3 18 days after the initial addition of Fe. Water-column integrated chl a was enhanced 8-fold, reaching a maximum of 114 mg m -2 on day 17. The resulting bloom is described in two ecological phases based on dominant phytoplankton groups. In Phase I, which encompassed the initial infusion up to day 10, all size-fractions (0.2-2, 2-20 and >20 ?m) increased in biomass as indicated by chl a, contributing to a surface standing stock of 2 mg m -3. In Phase II, from days 10 to 18, the bloom was dominated by microphytoplankton (>20 ?m), with a concomitant decrease in phytoplankton <20 ?m. Microphytoplankton, which initially accounted for 25% of the phytoplankton biomass and increased by a factor of 50, consisted primarily of the pennate diatom genera, Pseudo-nitzschia, Neodenticula and Thalassiothrix and the centric diatom genera, Chaetoceros, Rhizosolenia, and Proboscia. Particulate carbon-to-chl a (PC: chl a) ratios for large cells (?5 ?m) decreased 5-fold by day 18, indicative of enhanced cellular chl a content and increased phytoplankton contributions to PC. Pennate diatoms were most abundant in the patch, although when converted to biovolume, centric diatoms contributed larger amounts of algal carbon (C) to the bloom. A rapid decline in chl a on day 19 marked the onset of bloom decline. The magnitude, duration and composition of the phytoplankton response to the Fe enrichment clearly depicted a major shift in the structure of the algal assemblage and increased C export potential.

Marchetti, Adrian; Sherry, Nelson D.; Kiyosawa, Hiroshi; Tsuda, Atsushi; Harrison, Paul J.

2006-10-01

95

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

96

How to cope with your sulfur problems. [COPE process; use of oxygen enriched air to increase capacity  

Microsoft Academic Search

COPE (Claus Oxygen-based Process Expansion) technology presents an improvement to the modified Claus process that replaces air with up to 100% oxygen to debottleneck Claus Sulphur Recovery Unit's (SRU's). The major equipment requirements of the COPE process are the installation of an acid gas recycle blower and a proprietary burner. The recycle stream acts as a coolant to moderate reaction

B. G. Goar; W. P. Hegarty; T. W. Thew

1986-01-01

97

Safety aspects of gas centrifuge enrichment plants  

Microsoft Academic Search

Uranium enrichment by gas centrifuge is a commercially proven, viable technology. Gas centrifuge enrichment plant operations pose hazards that are also found in other industries as well as unique hazards as a result of processing and handling uranium hexafluoride and the handling of enriched uranium. Hazards also found in other industries included those posed by the use of high-speed rotating

1987-01-01

98

Commercial considerations in enriched uranium transactions  

SciTech Connect

This article is the third in a series of articles on the commercial considerations of uranium transactions. Previous articles have dealt with UF6 and conversion services (February 1994), and U3O8 (March 1988). The present article focuses on the commercial considerations associated with enriched uranium and the enrichment process. Within this article are discussions of the specifications, handling and transport, and commercial transactions for enrichment and enriched uranium products.

Ruthowski, E.; White, G. Jr.

1995-03-01

99

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

2013-05-18

100

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

101

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

102

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

103

A tethering mechanism controls the processivity and kinetochore-microtubule plus-end enrichment of the kinesin-8 Kif18A  

PubMed Central

Summary Metaphase chromosome positioning depends on Kif18A, a kinesin-8 that accumulates at and suppresses the dynamics of K-MT plus ends. By engineering Kif18A mutants that suppress MT dynamics but fail to concentrate at K-MT plus-ends, we identify a mechanism that allows Kif18A to accumulate at K-MT plus ends to a level required to suppress chromosome movements. Enrichment of Kif18A at K-MT plus-ends depends on its C-terminal tail domain, while the ability of Kif18A to suppress MT growth is conferred by the N-terminal motor domain. The Kif18A tail contains a second MT-binding domain that diffuses along the MT lattice, suggesting that it tethers the motor to the MT track. Consistently, the tail enhances Kif18A processivity and is crucial for it to accumulate at K-MT plus-ends. The heightened processivity of Kif18A, conferred by its tail domain, thus promotes concentration of Kif18A at K-MT plus-ends, where it suppresses their dynamics to control chromosome movements.

Stumpff, Jason; Du, Yaqing; English, Chauca A.; Maliga, Zoltan; Wagenbach, Michael; Asbury, Charles L.; Wordeman, Linda; Ohi, Ryoma

2011-01-01

104

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

2011-10-04

105

Novel process of fermenting black soybean [Glycine max (L.) Merrill] yogurt with dramatically reduced flatulence-causing oligosaccharides but enriched soy phytoalexins.  

PubMed

Black soybeans [Glycine max (L.) Merrill] were germinated under fungal stress with food grade R. oligosporus for 3 days and were homogenized and fermented with lactic acid bacteria (LAB) to produce soy yogurt. Fungal stress led to the generation of oxylipins [oxooctadecadienoic acids (KODES) isomers and their respective glyceryl esters] and glyceollins--a type of phytoalexins unique to soybeans. In soy yogurt, the concentrations of total KODES and total glyceollins were 0.678 mg/g (dry matter) and 0.953 mg/g, respectively. The concentrations of other isoflavones (mainly genistein and daidzein and their derivatives) in soy yogurt remained largely unchanged after the processes compared with the control soy yogurt. Germination of black soybean under fungal stress for 3 days was sufficient to reduce stachyose and raffinose (which cause flatulence) by 92 and 80%, respectively. With a pH value of 4.42, a lactic acid content of 0.262%, and a maximum viable cell count of 2.1 x 10 (8) CFU/mL in the final soy yogurt, soy milk from germinated soybeans under fungal stress was concluded to be a suitable medium for yogurt-making. The resulting soy yogurt had significantly altered micronutrient profiles with significantly reduced oligosaccharides and enriched glyceollins. PMID:18831591

Feng, Shengbao; Saw, Chin Lee; Lee, Yuan Kun; Huang, Dejian

2008-10-03

106

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

107

BLENDING LOW ENRICHED URANIUM WITH DEPLETED URANIUM TO CREATE A SOURCE MATERIAL ORE THAT CAN BE PROCESSED FOR THE RECOVERY OF YELLOWCAKE AT A CONVENTIONAL URANIUM MILL  

SciTech Connect

Throughout the United States Department of Energy (DOE) complex, there are a number of streams of low enriched uranium (LEU) that contain various trace contaminants. These surplus nuclear materials require processing in order to meet commercial fuel cycle specifications. To date, they have not been designated as waste for disposal at the DOE's Nevada Test Site (NTS). Currently, with no commercial outlet available, the DOE is evaluating treatment and disposal as the ultimate disposition path for these materials. This paper will describe an innovative program that will provide a solution to DOE that will allow disposition of these materials at a cost that will be competitive with treatment and disposal at the NTS, while at the same time recycling the material to recover a valuable energy resource (yellowcake) for reintroduction into the commercial nuclear fuel cycle. International Uranium (USA) Corporation (IUSA) and Nuclear Fuel Services, Inc. (NFS) have entered into a commercial relationship to pursue the development of this program. The program involves the design of a process and construction of a plant at NFS' site in Erwin, Tennessee, for the blending of contaminated LEU with depleted uranium (DU) to produce a uranium source material ore (USM Ore{trademark}). The USM Ore{trademark} will then be further processed at IUC's White Mesa Mill, located near Blanding, Utah, to produce conventional yellowcake, which can be delivered to conversion facilities, in the same manner as yellowcake that is produced from natural ores or other alternate feed materials. The primary source of feed for the business will be the significant sources of trace contaminated materials within the DOE complex. NFS has developed a dry blending process (DRYSM Process) to blend the surplus LEU material with DU at its Part 70 licensed facility, to produce USM Ore{trademark} with a U235 content within the range of U235 concentrations for source material. By reducing the U235 content to source material levels in this manner, the material will be suitable for processing at a conventional uranium mill under its existing Part 40 license to remove contaminants and enable the product to re-enter the commercial fuel cycle. The tailings from processing the USM Ore{trademark} at the mill will be permanently disposed of in the mill's tailings impoundment as 11e.(2) byproduct material. Blending LEU with DU to make a uranium source material ore that can be returned to the nuclear fuel cycle for processing to produce yellowcake, has never been accomplished before. This program will allow DOE to disposition its surplus LEU and DU in a cost effective manner, and at the same time provide for the recovery of valuable energy resources that would be lost through processing and disposal of the materials. This paper will discuss the nature of the surplus LEU and DU materials, the manner in which the LEU will be blended with DU to form a uranium source material ore, and the legal means by which this blending can be accomplished at a facility licensed under 10 CFR Part 70 to produce ore that can be processed at a conventional uranium mill licensed under 10 CFR Part 40.

Schutt, Stephen M.; Hochstein, Ron F.; Frydenlund, David C.; Thompson, Anthony J.

2003-02-27

108

The Discontinuous Enrichment Method  

Microsoft Academic Search

We propose a finite element based discretization method in which the standard polynomialfield is enriched within each element by a nonconforming field that is addedto it. The enrichment contains free-space solutions of the homogeneous differentialequation that are not represented by the underlying polynomial field. Continuity ofthe enrichment across element interfaces is enforced weakly by Lagrange multipliers.In this manner, we expect

Charbel Farhat; Isaac Harari; Leopoldo P. Franca

2000-01-01

109

The discontinuous enrichment method  

Microsoft Academic Search

We propose a finite element based discretization method in which the standard polynomial field is enriched within each element by a non-conforming field that is added to it. The enrichment contains free-space solutions of the homogeneous differential equation that are not represented by the underlying polynomial field. Continuity of the enrichment across element interfaces is enforced weakly by Lagrange multipliers.

Charbel Farhat; Isaac Harari; Leopoldo P. Franca

2001-01-01

110

Uranium enrichment and public policy  

Microsoft Academic Search

Alternative policies to the present government monopoly of the uranium enrichment process are discussed in this monograph. Alternative policies analyzed are continued government monopoly and operation by the Department of Energy, establishment of a government corporation, and complete relinquishing of government control with the private sector taking the risks of constructing additional capacity. The material is divided into 6 chapters.

1978-01-01

111

Organizational work-family resources as predictors of job performance and attitudes: the process of work-family conflict and enrichment.  

PubMed

The goal of the current study was to test a model where organizational resources (aimed at managing work and family responsibilities) predict job attitudes and supervisor ratings of performance through the mechanisms of work-family conflict and work-family enrichment. Employees (n = 174) at a large metropolitan hospital were surveyed at two time periods regarding perceptions of family supportive supervisor behaviors (FSSB), family supportive organizational perceptions (FSOP), bidirectional work-family conflict, bidirectional work-family enrichment, and job attitudes. Supervisors were also asked to provide performance ratings at Time 2. Results revealed FSSB at Time 1 predicted job satisfaction, organizational commitment and intention to leave, as well as supervisor ratings of performance, at Time 2. In addition, both work-family enrichment and family-work enrichment were found to mediate relationships between FSSB and various organizational outcomes, while work-family conflict was not a significant mediator. Results support further testing of supervisor behaviors specific to family support, as well models that include bidirectional work-family enrichment as the mechanism by which work-family resources predict employee and organizational outcomes. PMID:22149204

Odle-Dusseau, Heather N; Britt, Thomas W; Greene-Shortridge, Tiffany M

2011-12-12

112

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

113

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

114

Computational Fluid Mechanics in R and D on Uranium Enrichment.  

National Technical Information Service (NTIS)

Uranium enrichment represents an essential link in the cycle of nuclear fuels for power production. There are many processes of uranium enrichment, but three of them dominate the nuclear history as well in the past (Gaseous diffusion and centrifugation) a...

O. Soubbaramayer

1988-01-01

115

Effect of Enriched (Complex) Environment on Nerve Conduction Velocity: New Data and Review of Implications for the Speed of Information Processing.  

ERIC Educational Resources Information Center

Results with 54 mice confirm that increased stimulation or usage, as would be provided by environmental enrichment (EE), increases peripheral nerve conduction velocity. These results suggest a role at the physiological level for EE (or deprivation) in affecting measured intelligence. (SLD)

Reed, T. Edward

1993-01-01

116

Uranium Enrichment Export Control Guide: Gaseous Diffusion.  

National Technical Information Service (NTIS)

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 co...

1989-01-01

117

Considerations in the development of a process to manufacture low-enriched uranium foil fuel for the high flux isotope reactor  

SciTech Connect

A reference flow sheet is the one of the first planning steps in the development of a manufacturing capacity for low enriched uranium foil fuels and can be used to develop a work structure, a critical path schedule and identify development needs. The reference flow sheet presented is specific to the High Flux Isotope Reactor and is used to estimate the change in HFIR operating cost due to fuel conversion. (author)

Sease, J.D.; Primm, R.T. III [Research Reactors Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6399 (United States)], E-mail: seasejd@ornl.gov; Miller, J.H. [Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6399 (United States)

2008-07-15

118

Prospects for uranium enrichment  

Microsoft Academic Search

It is pointed out that the lack of suitable lasers constitutes the biggest technological barrier to practical laser techniques for the enrichment of uranium isotopes. Costs of laser isotope-separation techniques are compared with those of other approaches, taking into account as a basis conservative extrapolations of existing laser technology. Attention is given to the demand for enriched uranium, the types

R. J. Jensen; J. G. Marinuzzi; C. P. Robinson; S. D. Rockwood

1976-01-01

119

Foam flotation enrichment of enantiomers  

SciTech Connect

Adsorptive bubble separation methods are known to be useful for processing large amounts of material at a relatively low cost. These techniques have been used to enrich components from both heterogeneous and homogeneous solutions. There is a need for economical process-scale enantiomeric separations. Thus far there has been little evidence to support the feasibility of 2using an adsorptive bubble process to enrich enantiomers. We demonstrate that foam-forming chiral collectors can be used in conjunction with an inexpensive glass device to enantiomerically enrich some pharmaceutically important compounds as well as derivatized and underivatized amino acids. Factors that appeared to affect this water-based separation include the following: (a) column length, (b) column geometry and packing, (c) gas flow rate, (d) concentration of the collector and the racemate, (e) nature of the collector, (f) temperature, (g) pH, (h) reflux time, (i) foam dryness, and (j) the presence of other materials in the sample (e.g., miscible organic solvents, salts, etc.). The chiral collectors used in this study are known to be able to associate with analytes via ligand exchange interactions, hydrophobic inclusion complexation, and hydrogen-bonding interactions among others. 28 refs., 5 figs., 5 tabs.

Armstrong, D.W.; Zhou, E.Y.; Chen, S.; Le, K.; Tang, Y. (Univ. of Missouri, Rolla, MO (United States))

1994-12-01

120

Uranium Enrichment by Gas Centrifuge.  

National Technical Information Service (NTIS)

After recalling the physical principles and the techniques of centrifuge enrichment the report describes the centrifuge enrichment programs of the various countries concerned and compares this technology with other enrichment technologies like gaseous dif...

I. D. Heriot

1988-01-01

121

Uranium enrichment: heading for a cliff  

SciTech Connect

Thanks to drastic cost cutting in the past 2 years, US enrichment plants now have the lowest cost production in the world, but US prices are still higher than those of overseas competitors because the business is paying for past mistakes. The most serious difficulty is that the Department of Energy (DOE), which owns and operates the US enrichment enterprise, is paying more than $500 million a year to the Tennessee Valley Authority (TVA) for electricity it once thought it would need but no longer requires. Another is that billions of dollars were spent in the 1970s and early 1980s to build new capacity that is now not needed. As a result, the enrichment enterprise has accumulated a debt to the US Treasury that the General Accounting Office (GAO) estimates at $8.8 billion. This paper presents the background and current debate in Congress about the difficulties facing the enrichment industry. In the midst of this debate over the future of the enterprise, the development of the next generation of enrichment technology is being placed in jeopardy. Known as atomic vapor laser isotope separation, or AVLIS, the process was viewed as the key to the long-term competitiveness of US enrichment. As the federal deficit mounted, however, funding for the AVLIS program was cut back and the timetable was stretched out. The US enrichment program has reached the point at which Congress will be forced to make some politically difficult decisions.

Norman, C.

1987-05-22

122

Profile of World Uranium Enrichment Programs-2009  

SciTech Connect

It is generally agreed that the most difficult step in building a nuclear weapon is acquiring fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, whereas HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use as fuel for nuclear reactors to generate electricity. However, the same equipment used to produce LEU for nuclear reactor fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is not diverted or enriched to HEU. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 56 million kilogram separative work units (SWU) per year, with 22.5 million in gaseous diffusion and more than 33 million in gas centrifuge plants. Another 34 million SWU/year of capacity is under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique of the future but has yet to be demonstrated commercially. In the early 1980s, six countries developing gas centrifuge technology (United States, United Kingdom, Germany, the Netherlands, Japan, and Australia) along with the International Atomic Energy Agency and the European Atomic Energy Community began developing effective safeguards techniques for GCEPs. This effort was known as the Hexapartite Safeguards Project (HSP). The HSP had the goal of maximizing safeguards effectiveness while minimizing the cost to the operator and inspectorate, and adopted several recommendations, such as the acceptance of limited-frequency unannounced access inspections in cascade halls, and the use of nondestructive assay measurements and tamper-indicating seals. While only the HSP participants initially committed to implementing all the measures of the approach, it has been used as a model for the safeguards applied to GCEPs in additional states. Uranium enrichment capacity has continued to expand on all fronts in the last few years. GCEP capacity is expanding in anticipation of the eventual shutdown of the less-efficient GDPs, the termination of the U.S.-Russia HEU blend-down program slated for 2013, and the possible resurgence of nuclear reactor construction as part of an expected 'Nuclear Renaissance'. Overall, a clear trend in the world profile of uranium enrichment plant operation is the continued movement towards multinational projects driven by commercial and economic interests. Along this vein, the safeguards community is continuing to develop new safeguards techniques and technologies that are not overly burdensome to enrichment plant operators while delivering more effective and efficient results. This report provides a snapshot overview of world enrichment capacity in 2009, including profiles of the uranium enrichment programs of individual states. It is a revision of a 2007 report on the same topic; significant changes in world enrichment programs between the previous and current reports are emphasized. It is based entirely on open-source information, which is dependent on published sources and may theref

Laughter, Mark D [ORNL

2009-04-01

123

Safety aspects of gas centrifuge enrichment plants  

SciTech Connect

Uranium enrichment by gas centrifuge is a commercially proven, viable technology. Gas centrifuge enrichment plant operations pose hazards that are also found in other industries as well as unique hazards as a result of processing and handling uranium hexafluoride and the handling of enriched uranium. Hazards also found in other industries included those posed by the use of high-speed rotating equipment and equipment handling by use of heavy-duty cranes. Hazards from high-speed rotating equipment are associated with the operation of the gas centrifuges themselves and with the operation of the uranium hexafluoride compressors in the tail withdrawal system. These and related hazards are discussed. It is included that commercial gas centrifuge enrichment plants have been designed to operate safely.

Hansen, A.H.

1987-01-01

124

Cognitive Enrichment Network Overview.  

ERIC Educational Resources Information Center

|This article discusses the Cognitive Enrichment Network Model (COGNET) of elementary school instruction developed at the University of Tennessee at Knoxville. This model is largely based on the theory of mediated learning experience (MLE) developed by Israeli psychologist Reuven Feuerstein, which posits that learning is closely connected to…

Greenberg, Katherine H.

125

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.

126

EDUCATIONAL ENRICHMENT PROGRAM - 1964.  

ERIC Educational Resources Information Center

THE EDUCATIONAL ENRICHMENT PROGRAM - 1964 WAS A COOPERATIVE UNDERTAKING OF SIX INDEPENDENT SCHOOLS IN OR NEAR BOSTON AND A NUMBER OF INTERESTED ORGANIZATIONS THAT OFFERED THE USE OF THEIR FACILITIES AND PERSONNEL TO AN URBAN COMMUNITY DURING THE NONSCHOOL MONTHS. THE AIM OF THE PROGRAM WAS TO OFFER CHALLENGING AND EXPLORATORY STUDY WHICH COULD…

FUNK, JOHN H.

127

Profile of World Uranium Enrichment Programs - 2007  

SciTech Connect

It is generally agreed that the most difficult step in building a nuclear weapon is acquiring weapons grade fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, while HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use in fuel for nuclear reactors. However, the same equipment used to produce LEU for nuclear fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is only enriched to LEU, no undeclared LEU is produced, and no uranium is enriched to HEU or secretly diverted. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity, but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 53 million kg-separative work units (SWU) per year, with 22 million in gaseous diffusion and 31 million in gas centrifuge plants. Another 23 million SWU/year of capacity are under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique of the future, but has yet to be demonstrated commercially. In the early 1980s, six countries developing gas centrifuge technology (United States, United Kingdom, Germany, the Netherlands, Japan, and Australia) along with the International Atomic Energy Agency (IAEA) and the European Atomic Energy Community (EURATOM) began developing effective safeguards techniques for GCEPs. This effort was known as the Hexapartite Safeguards Project (HSP). The HSP had the goal of maximizing safeguards effectiveness while minimizing the cost to the operator and inspectorate, and adopted several recommendations, such as the acceptance of limited-frequency unannounced access (LFUA) inspections in cascade halls, and the use of nondestructive assay (NDA) measurements and tamper-indicating seals. While only the HSP participants initially committed to implementing all the measures of the approach, it has been used as a model for the safeguards applied to GCEPs in additional states. This report provides a snapshot overview of world enrichment capacity in 2007, including profiles of the uranium enrichment programs of individual states. It is based on open-source information, which is dependent on unclassified sources and may therefore not reflect the most recent developments. In addition, it briefly describes some of the safeguards techniques being used at various enrichment plants, including implementation of HSP recommendations.

Laughter, Mark D [ORNL

2007-11-01

128

Stable isotope enrichment in stratospheric nitrous oxide  

SciTech Connect

Nitrous oxide is a greenhouse gas that also plays a role in the cycling of stratospheric ozone. Air samples from the lower stratosphere exhibit {sup 15}N/{sup 14}N and {sup 18}O/{sup 16}O enrichment in nitrous oxide, which can be accounted for with a simple model describing an irreversible destruction process. The observed enrichments are quite large and incompatible with those determined for the main stratospheric nitrous oxide loss processes of photolysis and reaction with excited atomic oxygen. Thus, although no stratospheric source needs to be invoked, the data indicate that present understanding of stratospheric nitrous oxide chemistry is incomplete. 21 refs., 1 fig., 1 tab.

Rahn, T.; Wahlen, M. [Univ. of California San Diego, La Jolla, CA (United States)

1997-12-05

129

Low-resolution gamma-ray measurements of uranium enrichment  

SciTech Connect

Facilities that process special nuclear material perform periodic inventories. In bulk facilities that process low-enriched uranium, these inventories and their audits are based primarily on weight and enrichment measurements. Enrichment measurements determine the {sup 211}U weight fraction of the uranium compound from the passive gamma-ray emissions of the sample. Both international inspectors and facility operators rely on the capability to make in-field gamma-ray measurements of uranium enrichment. These users require rapid, portable measurement capability. Some in-field measurements have been biased, forcing the inspectors to resort to high-resolution measurements or mass spectrometry to accomplish their goals.

Sprinkle, J.K. Jr.; Christiansen, A.; Cole, R.; Collins, M.L. [and others

1996-11-01

130

The Enriched Xenon Observatory  

SciTech Connect

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

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

2009-12-17

131

The Enriched Xenon Observatory  

NASA Astrophysics Data System (ADS)

The Enriched Xenon Observatory (EXO) experiment will search for neutrinoless double beta decay of 136Xe. The EXO Collaboration is actively pursuing both liquid-phase and gas-phase Xe detector technologies with scalability to the ton-scale. The search for neutrinoless double beta decay of 136Xe is especially attractive because of the possibility of tagging the resulting Ba daughter ion, eliminating all sources of background other than the two neutrino decay mode. EXO-200, the first phase of the project, is a liquid Xe time projection chamber with 200 kg of Xe enriched to 80% in 136Xe. EXO-200, which does not include Ba-tagging, will begin taking data in 2009, with two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4×1025 years. This corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV.

Dolinski, M. J.

2009-12-01

132

Enriched Isotope Applications: Agricultural Field.  

National Technical Information Service (NTIS)

Enriched stable isotopes for tracer uses in agriculture and related fields were identified. Based on a survey of current studies and available world production capacity, the projected growth in isotope tracer applications was determined. Enriched stable i...

R. DeWitt

1980-01-01

133

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.

134

Gas separation membranes developed through integration of polymer blending and dual-layer hollow fiber spinning process for hydrogen and natural gas enrichments  

Microsoft Academic Search

This article describes the research study on exploitation of polymer blending technology and dual-layer hollow fiber spinning process for the fabrication of a novel class of high performance gas separation membranes. The specific functional material employed for this purpose is a polymer blend constructed of the interpenetrated networks of PBI and Matrimid. It is within the scope of this study

Seyed Saeid Hosseini; Na Peng; Tai Shung Chung

2010-01-01

135

Investigation of how agitation during precipitation, and subsequent processing affects the particle size distribution and separation of ?-lactalbumin enriched whey protein precipitates  

Microsoft Academic Search

In this work, ?-lactalbumin (?-la) rich precipitate particles are formed and aged in a batch stirred-tank from a whey protein concentrate (WPC) dispersion. Precipitation of the proteins occurs during a period of acid-addition followed by an ageing period. This study investigates how stirred-tank impeller agitation and subsequent processing, by means of passing precipitate suspensions through a capillary tube or a

Edmond P Byrne; John J Fitzpatrick

2002-01-01

136

Parents as Partners in Art Education Enrichment  

ERIC Educational Resources Information Center

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

Hansen, Laurie

2008-01-01

137

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

138

High-resolution spectroscopic observations of two s-process-enriched and carbon-poor post-AGB stars: GLMP 334 and IRAS 15482-5741  

NASA Astrophysics Data System (ADS)

Aims: The study of post-AGB stars provides important information on the s-process inside asymptotic giant branch (AGB) stars. We determined the atmospheric parameters and abundance patterns of two post-AGB stars: GLMP 334 and IRAS 15482-5741 to better understand their evolutionary state and the nature of the s-element enhancement of these stars. Methods: We used high-resolution optical spectroscopy. Atmospheric parameters and abundances were determined in the local-thermodynamic-equilibrium model atmospheres of Kurucz (1993, CD-ROM 13, SAO) using the spectral analysis code MOOG. Spectroscopic observations are compared with nucleosynthesis AGB models of different initial masses and s-process efficiencies. Results: Theoretical interpretations are presented and discussed. The observed distribution of neutron capture elements can be fitted with particular choices of AGB initial masses and of the 13C neutron source (13C-pocket strengths) obtained at the adopted [Fe/H] for each star, but the low [C/Fe] observed is incompatible with model predictions. The problem can be solved by increasing the metallicity by 0.2 dex, which is inside the spectroscopic uncertainty. The abundances of carbon and nitrogen observed in these stars may support the occurrence of an extra-mixing episode, the "cool bottom process", even if its exact effect cannot be theoretically quantified yet. Based on observations made with the 2.2 m telescope at the European Southern Observatory (La Silla, Chile).Tables 2, 4 and Appendix A are available in electronic form at http://www.aanda.org

Pereira, C. B.; Gallino, R.; Bisterzo, S.

2012-02-01

139

Detection of uranium enrichment activities using environmental monitoring techniques  

SciTech Connect

Uranium enrichment processes have the capability of producing weapons-grade material in the form of highly enriched uranium. Thus, detection of undeclared uranium enrichment activities is an international safeguards concern. The uranium separation technologies currently in use employ UF{sub 6} gas as a separation medium, and trace quantities of enriched uranium are inevitably released to the environment from these facilities. The isotopic content of uranium in the vegetation, soil, and water near the plant site will be altered by these releases and can provide a signature for detecting the presence of enriched uranium activities. This paper discusses environmental sampling and analytical procedures that have been used for the detection of uranium enrichment facilities and possible safeguards applications of these techniques.

Belew, W.L.; Carter, J.A.; Smith, D.H.; Walker, R.L.

1993-03-30

140

Energy consumption of chemical uranium enrichment  

SciTech Connect

A quantitative study of chemical separation energy for enriching uranium-235 by the redox chromatography was conducted. Isotope exchange reactions between UU -UO2S ions in the enrichment column are maintained by the redox reactions. The chemical separation energy is ultimately supplied by hydrogen and oxygen gas for regenerating redox agents. The redox energy for the isotope separation is theoretically predicted as a function of the dynamic enrichment factor observed in the chromatographic development of uranium adsorption band. Thermodynamic treatments of the equilibrium reactions implies and inverse redox reaction which can be enhanced by the chemical potential of the ion-exchange reaction of oxidant. Experimental results showed 30 to 90% recovery of the redox energy by the inverse reaction. These results will devise a simplified redox chromatography process where a number of columns in one module is reduced.

Miyake, T.; Takeda, K.; Obanawa, H.

1987-01-01

141

Application of sequential probability ratio test to uranium enrichment verification  

NASA Astrophysics Data System (ADS)

The sequential probability ratio test is a statistical process capable of quickly and accurately verifying the uranium enrichment in the header pipes of uranium centrifuge enrichment facilities. The test minimizes the time required for a measurement, making a complete verification possible in 15-30 min.

Pratt, J. C.; Close, D. A.

1987-08-01

142

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

Lachmann, Alexander; Ma'ayan, Avi

2009-01-01

143

Validation of MCNP4a for highly enriched uranium using the Battelle process safety and risk management IBM RS/6000 workstation  

SciTech Connect

This document has been prepared to allow use of the Radiation Shielding and Information Center (RSIC) release of MCNP4a, which has been installed on the Battelle Process Safety and Risk Management (PSRM) IBM RS/6000 workstation, for production calculations for the Portsmouth Gaseous Diffusion Plant (PORTS). This hardware/software configuration is under the configuration control plan listed in Reference 1. The first portion of this document outlines basic information with regard to validation of MCNP4a using the supplied cross sections and the additional MCNPDAT cross sections. A basic discussion of MCNP is provided, along with discussions of the validation database in general. A description of the statistical analysis then follows. The results of this validation indicate that the software and data libraries examined may be used with confidence for criticality calculations at the Portsmouth Gaseous Diffusion Plant (PORTS). When the validation results are treated as a single group, there is a 95% confidence that 99.9% of future calculations of similar critical systems will have a calculated k{sub eff} > 0.95. Based on this result, the Battelle PSRM Nuclear Safety Group has adopted the calculational acceptance criteria that a calculated k{sub eff} + 2{sigma}, {le} 0.95 is safely subcritical. The conclusion of this document is that MCNP4a and all associated cross section libraries installed on the PSRM IBM RS/6000 are acceptable for use in performing production criticality safety calculations for the Portsmouth Gaseous Diffusion Plant.

Negron, S.B.; Lee, B.L. Jr.; Tayloe, R.W. Jr.

1996-01-01

144

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

145

Withdrawal assay monitoring at US Enrichment Facilities  

SciTech Connect

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

Smith, D.E.

1996-01-01

146

Work Enrichment for Academic Libraries.  

ERIC Educational Resources Information Center

|Explores important quality of work life strategy--job redesign--and discusses job enlargement and job enrichment. A case study of academic library personnel demonstrates how introduction of automated systems at University of California, Berkeley led to restructuring and enrichment of jobs. References and list of selected resources are appended.…

Martell, Charles; Untawale, Mercedes

1983-01-01

147

Methanogenesis from acetate: enrichment studies.  

PubMed Central

An acetate enrichment culture was initiated by inoculating anaerobic sludge from a mesophilic methane digestor into a mineral salts medium with calcium acetate as the sole carbon and energy source. This enrichment was maintained indefinitely by weekly transfer into medium of the same composition. A study of this enrichment disclosed an unexpected age-dependent inhibition of methanogenesis by H2 and formate which apparently differed from the inhibition by chloroform and benzyl viologen. This age-dependent inhibition indicated that microbial interactions of the mixed enrichment population may play a regulatory role in methane formation. Futhermore, stimulation of methanogenesis in the acetate enrichment by addition of yeast extract showed a nutrient limitation which indicated that syntrophic interactions leading to formation of growth factors may also occur. A model is presented to illustrate the possible interrelationships between methanogenic and nonmethanogenic bacteria in their growth and formation of methane and carbon dioxide from acetate. Images

Baresi, L; Mah, R A; Ward, D M; Kaplan, I R

1978-01-01

148

Laser enrichment of carbon-14  

NASA Astrophysics Data System (ADS)

An experimental study has been performed of the carbon-14 enrichment achievable in the ultraviolet laser dissociation of mixtures of14CH2O and12CH2O. The14C:12C enrichment factor in the CO product has been measured at 352.2 nm as a function of laser linewidth, formaldehyde temperature and pressure, and degree of carbon-14 depletion. The enrichment decreases with an increase in each of these parameters; the highest enrichment, 1190, was measured at 0.02 cm-1, 303 K, 1 Torr and a14C depletion of 10%. The results are assessed in terms of their application to radiocarbon dating, in particular for groundwater dating required for nuclear waste disposal, and to the enrichment of14C operating wastes extracted from nuclear reactors to a level suitable for commercial sale.

Mannik, L.; Brown, S. K.

1985-06-01

149

Neutron methods for monitoring the blending of enriched UF6 gas  

Microsoft Academic Search

Blending a highly enriched UF6 gas stream with low-enrichment material reduces the excess supply of highly enriched uranium that must be closely controlled for nonproliferation of nuclear weapons. Computer simulations and feasibility experiments show that inducing fission in 235U provides means for monitoring the blending process. Detecting delayed fission neutrons or gamma rays after fission products drift downstream in the

C. Stromswold; A. J. Peurrung; P. L. Reeder; D. S. Sunberg

1997-01-01

150

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

151

Analysis of enrichment factor of uranium enrichment by Redox chromatography  

SciTech Connect

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 a biased distribution of uranium ions between the solid and liquid phases and a nonequilibrium state in the separation column, thus allowing elucidation of the separation mechanism. A theoretical description of the central role of this enrichment factor in determining plant size and economics is presented.

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

1986-04-01

152

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

153

Ion exchange enrichment of uranium isotopes  

SciTech Connect

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 oxidizing agent zone, the uranium adsorption zone advancing through the anion exchanger, effecting reduction at the boundary (A) and/or effecting oxidation at the boundary (B), thereby effecting enrichment adjacent said boundary, and separating a fraction enriched in one of said isotopes, which process comprises using as the solvent medium a composition comprising (A) a solvent having a dielectric constant of at least 80 at 20* C., (B) hydrochloric acid and (C) at least one of hydrobromic acid and sulfuric acid, the solvent medium having a hydrogen ion concentration of about 0.1 m/l to about 10 m/l, a total chlorine ion concentration of about 0.1 m/l to about 12 m/l, at least one of bromine and sulfate ion being present in about 0.01 m/l to about 10 m/l and the other being present in from zero up to 10 m/l, and passing the materials through the ion exchanger at a rate such that the migration velocity of the uranium adsorption zone through the ion exchanger is at least about 1 cm per minute.

Miyake, T.; Onitsuka, H.; Takeda, K.

1983-01-11

154

Potential Exposures from Uranium Enrichment.  

National Technical Information Service (NTIS)

Public radiation doses resulting from gaseous diffusion enrichment facility effluents can be assessed by considering the potential environmental exposure pathways. These exposure pathways result from releases to both air and water, and rely on model evalu...

W. E. Kennedy

1987-01-01

155

Uranium-enrichment pricing policies  

SciTech Connect

Auditors found that the interest expense used in uranium enrichment pricing is based on the average rate Treasury pays on all Government issues outstanding, regardless of when they were issued, or for what purpose. Use of the Treasury's prevailing market rate would better ensure that enrichment prices more closely reflect actual costs incurred. Auditors also noted that in Fiscal Years 1979 through 1981, the interest charged on Government-owned feedstock added $515 million to enrichment costs, accounting for 32 percent of the Activity's interest costs and 12 percent of its total costs - costs that are passed on to customers in the form of higher prices. This was in response to a 1978 GAO recommendation. The Deputy Assistant Secretary for Uranium Enrichment and Assessment disagreed with the first finding but concurred in the second. His views are discussed.

Not Available

1983-07-06

156

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.

157

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

158

Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate  

PubMed Central

Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U-13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07%) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17%) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16%). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08%) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ± 0.17%). Plasma free palmitate enrichment was ?2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling.

Zhang, Xiao-jun; Rodriguez, Noe A.; Wang, Lijian; Tuvdendorj, Demidmaa; Wu, Zhanpin; Tan, Alai; Herndon, David N.; Wolfe, Robert R.

2012-01-01

159

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

160

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

161

Temperature dependence for anammox bacteria enriched from freshwater sediments.  

PubMed

The anoxic ammonium oxidation (anammox) process has been regarded as an attractive alternative process to treat wastewater containing high ammonium concentrations. By the implementation of anammox process at moderately low temperatures (<25°C), the anammox process will be applied to more various industrial wastewater treatments. In this study, we established enrichment cultures of anammox bacteria from freshwater sediments by using an up-flow column reactor equipped with porous polyester nonwoven fabric at moderately low temperatures. Their nitrogen conversion rates reached 0.07-0.26 kg-N/m³/d. Phylogenetic analysis based on 16S rRNA gene from enrichment cultures revealed the presence of various anammox bacteria affiliated with unknown anammox bacteria as well as known anammox candidates, i.e., Candidatus Kuenenia stuttgartiensis and Candidatus Brocadia fulgida, Candidatus Scalindua wagneri. Anammox bacterial populations were influenced by enrichment conditions, i.e., seed sediments and temperature. PMID:22652085

Osaka, Toshifumi; Kimura, Yuya; Otsubo, Yosuke; Suwa, Yuichi; Tsuneda, Satoshi; Isaka, Kazuichi

2012-05-29

162

Advanced technology for enrichment monitoring for gas centrifuge enrichment plants  

Microsoft Academic Search

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

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

2009-01-01

163

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

164

Potential exposures from uranium enrichment  

SciTech Connect

Public radiation doses resulting from gaseous diffusion enrichment facility effluents can be assessed by considering the potential environmental exposure pathways. These exposure pathways result from releases to both air and water, and rely on model evaluations to predict environmental transport. For most airborne releases, inhalation is the primary exposure pathway. Secondary pathways, including external exposure during plume passage, ingestion of uranium deposited on or contained in vegetation, and external exposure to uranium deposited on land surfaces also contribute. For liquid effluents, the primary exposure pathway is ingestion of drinking water, with secondary contributions to dose from ingestion of aquatic biota and ingestion of irrigated vegetation. This paper reviews the important considerations for conducting collective dose assessments for gaseous diffusion enrichment facility operations, including a discussion of the dosimetric considerations for uranium and a summary of estimated collective doses resulting from gaseous diffusion enrichment in the United States. 11 refs., 2 figs., 4 tabs.

Kennedy, W.E. Jr.

1987-09-01

165

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

166

Peak fitting applied to low-resolution enrichment measurements  

SciTech Connect

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

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

1998-12-01

167

SOLUBLE POISONS FOR SLIGHTLY ENRICHED URANIUM SYSTEMS  

DOEpatents

A study of B and Th poisoning of slightly enriched U/sup 235/ hetcrogeneous and homogencous systems has been made. This study indicates large processing plant capacity increases are possible by the incorporation of soluble neutron poisons. A tabulation of other readily available neutron poisons together with their poisoning effects has been made. The importance of being able to remove the ncutron poisons when desired as well as having them present under all conditions where nuclear safety is dependent upon them has also been presented. (auth)

Ketzlach, N.

1957-05-01

168

Day Care Center Enrichment Program.  

ERIC Educational Resources Information Center

|This guide to a West Virginia Department of Welfare project for upgrading the quality of day care centers throughout the state presents samples of the forms used in the program, accompanied by a brief description of the program's format, requirements and procedures. The Day Care Center Enrichment Program provides a monetary incentive for…

West Virginia State Dept. of Welfare, Charleston.

169

Enrichment for Nonhuman Primates: Baboons.  

National Technical Information Service (NTIS)

This book serves as an introduction to the basic behavior and environmental enrichment of a specific species of nonhuman primates that are more commonly used in education, research and entertainment. In many ways, this book is meant to be a how to manual;...

L. Brent T. M. Butler

2005-01-01

170

Enrichment Tours in Physical Education.  

ERIC Educational Resources Information Center

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

McCarthy, Jean

1980-01-01

171

Day Care Center Enrichment Program.  

ERIC Educational Resources Information Center

This guide to a West Virginia Department of Welfare project for upgrading the quality of day care centers throughout the state presents samples of the forms used in the program, accompanied by a brief description of the program's format, requirements and procedures. The Day Care Center Enrichment Program provides a monetary incentive for…

West Virginia State Dept. of Welfare, Charleston.

172

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

173

Pre-freshman enrichment program.  

National Technical Information Service (NTIS)

This document contains course outlines for a 4-week academic enrichment program for high school students. The courses were held at the Summer Academy for Young Scholars at the County College of Morris in Randolph, New Jersey. Class topics included the Int...

1997-01-01

174

Musicals Enrich Middle School Programs  

ERIC Educational Resources Information Center

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

Thomas, Douglas D.; North, Rita

2005-01-01

175

Mortality among Uranium Enrichment Workers.  

National Technical Information Service (NTIS)

A retrospective cohort mortality study was conducted on workers at the Portsmouth Uranium Enrichment facility (SIC-1094) in Pike County, Ohio, in response to a request from the Oil, Chemical and Atomic Workers International Local 3-689 for information on ...

D. P. Brown T. Bloom

1987-01-01

176

Components of uranium enrichment plant  

Microsoft Academic Search

A cross-linked product of ethylene-hexafluoropropylene copolymer is a good elastic material and has excellent resistance to attack by uranium hexafluoride even at a high temperature. Components made of said copolymer exhibit surprisingly long life, when used in a uranium enrichment plant.

M. Ito; S. Machi; G. Okamoto; K. Shirayama

1981-01-01

177

Experimental studies of sediment enrichment of arctic ice covers due to wave action and frazil entrainment  

Microsoft Academic Search

Two processes are investigated that are believed to contribute to the sediment enrichment of ice covers in coastal arctic waters. One process results from wave action which pumps sediment rich underlying water into he surface cover. The other enriching mechanism is produced by rising frazil that entrains suspended sediment which subsequently becomes incorporated in the surface ice layer. In both

Norbert L. Ackermann; Huang Tao Shen; Brian Sanders

1994-01-01

178

Deuterium Enrichment in Stratospheric Molecular Hydrogen  

NASA Astrophysics Data System (ADS)

Molecular hydrogen (H2) is the second most abundant reduced gas in the atmosphere (after methane) with a globally averaged mixing ratio of ~ 530 ppbv. Its largest source is believed to be photochemical oxidation of methane (C H4) and non-methane hydrocarbons (NMHCs); other recognized sources include biomass burning, fossil fuel burning, nitrogen fixation, and ocean degassing. As with other atmospheric trace gases, the stable isotopic content of H2 has the potential to help quantify various aspects of its production and destruction. The average deuterium content of H2 (expressed as ?DH2) is enriched by ~110 ‰ relative to Vienna Standard Mean Ocean Water while CH4 in the troposphere, the precursor for photochemical H2 production, is depleted by ~ 90 ‰ relative to V-SMOW and similar values are expected for NMHCs. Both natural and anthropogenic combustion sources of H2 have been shown to be depleted in deuterium by 200 to 300 ‰ (Gerst and Quay, 2001; Rahn et al., 2002), and the ocean and N2 fixation sources are expected to be in near thermodynamic equilibrium with local H2O and should have deuterium levels of ~-700 ‰ (Rahn et al., 2002). In order to offset these deuterium depleted sources and account for the observed tropospheric ?DH2, the balancing loss processes must discriminate against reaction with HD and/or the total fractionation associated with CH4 oxidation and the subsequent reactions leading to H2 must favor production of deuterated H2. We have analyzed a suite of stratospheric air samples in order to investigate the photochemical processes influencing the deuterium content of H2. While the mixing ratio of H2 is nearly constant, the deuterium content increases such that ?D=440 ‰ in samples with a stratospheric mean age of ~6 years. The constant mixing ratio results from the fact that production due to CH4 oxidation and loss due to H2 oxidation are approximately equal. The observed trend in ?D of stratospheric H2 can only be accounted for by an enrichment in the ratio of D to H of H2 relative to that in precursor CH4 in addition to the enrichment due to the slower oxidation of deuterated H2. We calculate the fractionation associated with this enrichment to be ?Total=1.54. As with other trace gases, in situ photochemical processes and the return flux of air from the stratosphere must be accounted for to explain tropospheric observations. Gerst, S., and P. Quay, J. Geophys. Res., 106, 5021-5031, 2001. Rahn, T., N. Kitchen, and J. M. Eiler, Geochim. Cosmochim. Acta, 66, 2475-2481, 2002.

Rahn, T.; Eiler, J.; McCarthy, M. C.; Boering, K. A.; Wennberg, P.; Atlas, E.; Donnelly, S.; Schauffler, S.

2002-12-01

179

A metaphor-enriched social cognition.  

PubMed

Social cognition is the scientific study of the cognitive events underlying social thought and attitudes. Currently, the field's prevailing theoretical perspectives are the traditional schema view and embodied cognition theories. Despite important differences, these perspectives share the seemingly uncontroversial notion that people interpret and evaluate a given social stimulus using knowledge about similar stimuli. However, research in cognitive linguistics (e.g., Lakoff & Johnson, 1980) suggests that people construe the world in large part through conceptual metaphors, which enable them to understand abstract concepts using knowledge of superficially dissimilar, typically more concrete concepts. Drawing on these perspectives, we propose that social cognition can and should be enriched by an explicit recognition that conceptual metaphor is a unique cognitive mechanism that shapes social thought and attitudes. To advance this metaphor-enriched perspective, we introduce the metaphoric transfer strategy as a means of empirically assessing whether metaphors influence social information processing in ways that are distinct from the operation of schemas alone. We then distinguish conceptual metaphor from embodied simulation--the mechanism posited by embodied cognition theories--and introduce the alternate source strategy as a means of empirically teasing apart these mechanisms. Throughout, we buttress our claims with empirical evidence of the influence of metaphors on a wide range of social psychological phenomena. We outline directions for future research on the strength and direction of metaphor use in social information processing. Finally, we mention specific benefits of a metaphor-enriched perspective for integrating and generating social cognitive research and for bridging social cognition with neighboring fields. PMID:20822208

Landau, Mark J; Meier, Brian P; Keefer, Lucas A

2010-11-01

180

Disposition of excess highly enriched uranium status and update  

SciTech Connect

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 it into commercial nuclear fuel or low-level radioactive waste are described. The resultant quantities of low enriched fuel material expected from processing are given, as well as the estimated schedule for introducing the material into the commercial reactor fuel market. 2 figs., 3 tabs.

Williams, C.K. III; Arbital, J.G.

1997-09-01

181

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

182

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

183

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.

184

Stable Isotope Inventory Requirements and Enrichment Capabilities.  

National Technical Information Service (NTIS)

The electromagnetic isotope enrichment program established in 1945 has since then continued to provide enriched stable, actinide, and selected radioactive isotopes. These unique materials used in research and medicine and for industrial applications are m...

W. A. Bell J. G. Tracy

1985-01-01

185

Cold start fuel enrichment circuit  

SciTech Connect

A cold start and knock prevention circuit is described having an output node providing a fuel enrichment signal for an internal combustion engine, comprising in combination: transducer means sensing audio signals indicative of engine combustion and occurring within a combustion chamber of the engine and converting the audio signals into an electrical output voltage including a portion representing background noise and a portion representing detonation; means for adjust the amplitude of the transducer output voltage; means sampling the portion of the transducer output voltage representing background noise and controlling the adjusting means to decrease the amplitude of the transducer output voltage for increased sensed background noise and to increase the amplitude of the transducer output voltage for decreased sensed background noise; detonation threshold means responsive to a predetermined increase in the amplitude of the portion of the transducer output voltage representing detonation above the amplitude of the portion of the transducer output voltage representing background noise, and outputting a fuel enrichment signal to the output node; a thermistor connected to the output node and sensing engine temperature; a voltage source biasing the thermistor such that the voltage across the thermistor varies with engine temperature and provides an output fuel enrichment signal at the output node.

Staerzi, R.E.; Radtke, N.H.; Hummel, L.S.

1988-08-16

186

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

187

Inhomogeneous chemical enrichment of the universe  

NASA Astrophysics Data System (ADS)

Elemental and isotopic abundances are the fossils of galactic archaeology. The observed [X/Fe]-[Fe/H] relations in the Galactic bulge and disk and the mass-metallicity relation of galaxies are roughly reproduced with chemodynamical simulations of galaxies under the standard ?-CDM picture and standard stellar physics. The observed [Mn/Fe] will put a constraint on the progenitors of Type Ia Supernova, while [(Zn,Co)/Fe] will put a constraint on the fraction of hypernovae. The isotopic ratios such as 17,18O and 25,26Mg may require a refinement of modelling of supernova and asymptotic giant branch stars. The recent observation of the Carbon-rich Damped Lyman ? system can be reproduced only with faint core-collapse supernovae. This suggests that chemical enrichment by the first stars in the first galaxies is driven not by pair-instability supernovae but by core-collapse supernovae (~20-50Msolar). The observed F abundances can be reproduced with the neutrino processes of core-collapse supernovae. As in F, the observations of elemental abundances in small systems may requires further complications of chemical enrichment. In globular clusters the relative contribution from low-mass supernovae is smaller than in the field, while the contribution from massive supernovae is smaller in dwarf spheroidal galaxies than in the solar neighborhood.

Kobayashi, Chiaki

2012-11-01

188

Progress in alkaline peroxide dissolution of low-enriched uranium metal and silicide targets  

SciTech Connect

This paper reports recent progress on two alkaline peroxide dissolution processes: the dissolution of low-enriched uranium metal and silicide (U{sub 3}Si{sub 2}) targets. These processes are being developed to substitute low-enriched for high-enriched uranium in targets used for production of fission-product {sup 99}Mo. Issues that are addressed include (1) dissolution kinetics of silicide targets, (2) {sup 99}Mo lost during aluminum dissolution, (3) modeling of hydrogen peroxide consumption, (4) optimization of the uranium foil dissolution process, and (5) selection of uranium foil barrier materials. Future work associated with these two processes is also briefly discussed.

Chen, L.; Dong, D.; Buchholz, B.A.; Vandegrift, G.F. [Argonne National Lab., IL (United States). Chemical Technology Div.; Wu, D. [Univ. of Illinois, Urbana, IL (United States)

1996-12-31

189

Enriched workflow modelling and Stochastic Branch-and-Bound  

Microsoft Academic Search

Workflow systems provide means and techniques for modelling, designing, performing and controlling repetitive (business) processes. The quality of commercial workflow systems is usually determined to a large extent by their versatility and multi-purpose application. One of the current trends in improving workflow systems lies in enriching modelling methods and techniques in order to enlarge design alternatives.The need for such advanced

Karl Doerner; Walter J. Gutjahr; Gabriele Kotsis; Martin Polaschek; Christine Strauss

2006-01-01

190

Airborne effluent control at fuel enrichment, conversion, and fabrication plants  

Microsoft Academic Search

Uranium conversion, enrichment, and fuel fabrication facilities generate gaseous wastes that must be treated prior to being discharged to the atmosphere. Since all three process and\\/or handle similar compounds, they also encounter similar gaseous waste disposal problems, the majority of which are treated in a similar manner. Ventilation exhausts from personnel areas and equipment off-gases that do not contain corrosive

1976-01-01

191

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

192

Variance propagation at the Portsmouth Uranium Enrichment Plant  

Microsoft Academic Search

The uranium enrichment plant presents unique problems in variance propagation. Some of the commonly discussed sources of measurement uncertainty, such as scale calibration or analytical standardization, are of secondary importance, while a variety of effects often classed as non-measurement'' sources of uncertainty or process variation'' dominate the variance propagation equation. Examples include attempts to define a smooth cascade gradient based

D. A. Shisler; R. E. Johns; J. Lovett

1992-01-01

193

Variance propagation at the Portsmouth Uranium Enrichment Plant  

Microsoft Academic Search

The uranium enrichment plant presents unique problems in variance propagation. Some of the commonly discussed sources of measurement uncertainty, such as scale calibration or analytical standardization, are of secondary importance, while a variety of effects often classed as ``non-measurement`` sources of uncertainty or ``process variation`` dominate the variance propagation equation. Examples include attempts to define a smooth cascade gradient based

D. A. Shisler; R. E. Johns; J. Lovett

1992-01-01

194

Formation of radioactivity enriched soils in mountain areas  

Microsoft Academic Search

A field study was carried out in the Mercantour Mountains at 2200 m altitude to investigate the processes of soil enrichment in atmospheric Chernobyl 137Cs. Soils with high 137Cs activities have been collected in the pasture areas with frequently measured 137Cs activity values of the order of 7000 Bq m?2. At some single spots (about 6% of the studied area),

Laurent Pourcelot; Didier Louvat; François Gauthier-Lafaye; Peter Stille

2003-01-01

195

Oxygen-enriched air production for MHD power plants  

NASA Astrophysics Data System (ADS)

An analysis of several of the cryogenic air separation process cycle variations and compression schemes designed to minimize net system power requirements for supplying pressurized, oxygen-enriched air to the combustor of a 2000 MWt (coal input) baseload MHD power plant is presented.

1980-05-01

196

Availability of enriched stable isotopes: present status and future prospects  

SciTech Connect

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

Hoff, R.W.

1986-09-18

197

Assay of low-enriched uranium using spontaneous fission neutrons  

SciTech Connect

Low-enriched uranium oxide in bulk containers can be assayed for safeguards purposes, using the neutrons from spontaneous fission of /sup 238/U as a signature, to complement enrichment and mass measurement. The penetrability of the fast fission neutrons allows the inner portion of bulk samples to register. The measurement may also be useful for measuring moisture content, of significance in process control. The apparatus used can be the same as for neutron correlation counting for Pu assay. The neutron multiplication observed in /sup 238/U is of intrinsic interest.

Zucker, M.S.; Fainberg, A.

1980-01-01

198

Theoretical analysis of aqueous residues incineration with oxygen enriched flames  

SciTech Connect

The use of oxygen to enrich the oxidizer can be an attractive alternate to increase incineration rates of a combustion chamber originally designed to operate with air. For a certain fuel flow rate, if some incineration parameters are held constant (as combustion chamber temperature, turbulence level, and residence time), an increase of incineration rates becomes possible with injection of oxygen. This work presents a theoretical evaluation of combustion air enrichment in a combustion chamber designed to incinerate aqueous residues using methane as fuel and air as oxidizer. Detailed chemistry was employed to predict pollutants formation. The overall process was investigated using the PSR routine from the CHEMKIN library.

Lacava, P.T.; Pimenta, A.P.; Veras, C.A.G.; Carvalho, J.A. Jr.

1999-10-01

199

Carbon dioxide enrichment of greenhouse crops  

SciTech Connect

In this volume, the author discusses the following: Worldwide Status and History of CO/sub 2/ Enrichment. CO/sub 2/ Enrichment in the Netherlands. CO/sub 2/ Enrichment in Some Countries of Eastern Europe: Research and Practical Application. CO/sub 2/ Enrichment in the United States. CO/sub 2/ Enrichment in Norway. CO/sub 2/ Measurement and Control. CO/sub 2/ Sources and Problems in Burning Hydrocarbon Fuels for CO/sub 2/ Enrichment. Organic Materials Degradation for CO/sub 2/ Enrichment of Greenhouse Crops. Dynamic Optimalization of CO/sub 2/ Concentration in Relation to Climate Control in Greenhouses. Units Conversion. International Currency Exchange Rates. Index.

Enoch, H.Z.; Kimball, B.A.

1986-01-01

200

Increasing the performance of tritium analysis by electrolytic enrichment.  

PubMed

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

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

2009-06-01

201

The paradox of enrichment in phytoplankton by induced competitive interactions.  

PubMed

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

2013-10-03

202

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.

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

203

A new era in U. S. uranium enrichment  

SciTech Connect

Complex market conditions, including lower than anticipated electrical growth rates, creation of a large spot market of enriched uranium, fluctuations in currency exchange rates, and certain political considerations, have created an unstable market for all primary producers, including the United States. In response to these conditions, the Department of Energy made significant changes to the U.S. program including the issuance of the Utility Services contract on January 18, 1984. Other major changes include redirecting research and development efforts on the advanced gas centrifuge and atomic vapor laser isotope separation processes, rescoping of the Gas Centrifuge Enrichment Plant project, and reevaluation of the operational mode of the three gaseous diffusion plants. Taken together, we believe these actions will retain the U.S. position of leadership in uranium enrichment. In summary, we plan to compete--through introduction of the world's most advanced, lowest cost technology and through responsiveness to our customers' needs.

Longenecker, J.R.

1984-07-01

204

Oxygen-enriched air production for MHD power plants  

SciTech Connect

Direct coal-fired MHD/steam power plants using preheated, oxygen-enriched air offer the near-term potential of attractive power plant efficiencies, operating flexibility, and improved reliability compared to plants with separately-fired or directly-heated air preheaters. Systems analyses of various MHD/steam power plants indicate that maximum plant efficiency is achieved by directly preheating combustion air with high temperature combustion products from the MHD topping cycle. However, difficulties in developing regenerative preheater materials to continuously withstand the corrosive, erosive, and fouling action of hot potassium and slag-laden gases preclude the use of directly-heated high temperature air preheaters in first generation MHD plants. Previously, high power consumption for oxygen production has limited the consideration of oxygen enrichment for MHD application. Therefore, the Magnetohydrodynamics Division of the Department of Energy (DOE/MHD) requested Gilbert Associates, Inc. (GAI) to develop and then analyze information on minimum power requirements and plant costs for oxygen production for a range of oxygen enrichments and delivery pressures. Such information will facilitate evaluation of oxygen-enriched MHD system performance and economics. An analysis of several of the cryogenic air separation process cycle variations and compression schemes that have been designed to minimize net system power requirements for supplying pressurized, oxygen-enriched air to the combustor of a 2000 MWt (coal input) baseload MHD power plant is presented. (WHK)

Not Available

1980-05-01

205

Dynamic p-enrichment schemes for multicomponent reactive flows  

NASA Astrophysics Data System (ADS)

We present a family of p-enrichment schemes. These schemes may be separated into two basic classes: the first, called fixed tolerance schemes, rely on setting global scalar tolerances on the local regularity of the solution, and the second, called dioristic schemes, rely on time-evolving bounds on the local variation in the solution. Each class of p-enrichment scheme is further divided into two basic types. The first type (the Type I schemes) enrich along lines of maximal variation, striving to enhance stable solutions in "areas of highest interest." The second type (the Type II schemes) enrich along lines of maximal regularity in order to maximize the stability of the enrichment process. Each of these schemes are tested on three model systems. The first is an academic exact system where basic analysis is easily performed. Then we discuss a pair of application model problems arising in coastal hydrology. The first being a contaminant transport model, which addresses a declinature problem for a contaminant plume with respect to a bay inlet setting. And the second, a multicomponent chemically reactive flow model of estuary eutrophication arising in the Gulf of Mexico.

Michoski, C.; Mirabito, C.; Dawson, C.; Wirasaet, D.; Kubatko, E. J.; Westerink, J. J.

2011-12-01

206

Mechanisms of enrichment of natural radioactivity along the beaches of the Camargue, France  

Microsoft Academic Search

A field study was carried out along the Golfe du Lion, that focussed on the beaches of the Camargue, to locate the main areas where enriched U and Th are found, and to better understand the processes that concentrate radioactivity on beaches. Indeed enriched areas are observed on some Camargue beaches, where high-dose rates are recorded due to excess U

C. Vassas; L. Pourcelot; C. Vella; J. Carpéna; J.-P. Pupin; P. Bouisset; L. Guillot

2006-01-01

207

Boron Enrichment in Martian Clay  

PubMed Central

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

Nagashima, Kazuhide; Freeland, Stephen J.

2013-01-01

208

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

2013-06-06

209

DESCRIPTION AND OPERATION OF AN INSTALLATION FOR THE PRODUCTION OF UâOâ FROM URANIUM HEXAFLUORIDE ENRICHED 20% IN U²³⁵  

Microsoft Academic Search

ABS>The general characteristics of installations working with enriched U ; are indicated with respect to the requirements for safety and health physics. ; The process and installation for the production of enriched of UâOâ ; for the fabrication of fuel elements are described. The process uses enriched UF\\/; sub 6\\/ in a batch procedure. The UâOâ obtained fulfills the ;

J. L. del Val Cid; J. M. R. Vega; J. M. C. Casado

1962-01-01

210

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

211

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

212

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

213

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2010 CFR

...2009-07-01 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...

2009-07-01

214

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

215

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

216

Phytoalexin-enriched functional foods.  

PubMed

Functional foods have been a developing area of food science research for the past decade. Many foods are derived from plants that naturally contain compounds beneficial to human health and can often prevent certain diseases. Plants containing phytochemicals with potent anticancer and antioxidant activities have spurred development of many new functional foods. This has led to the creation of functional foods to target health problems such as obesity and inflammation. More recent research into the use of plant phytoalexins as nutritional components has opened up a new area of food science. Phytoalexins are produced by plants in response to stress, fungal attack, or elicitor treatment and are often antifungal or antibacterial compounds. Although phytoalexins have been investigated for their possible role in plant defense, until recently they have gone unexplored as nutritional components in human foods. These underutilized plant compounds may possess key beneficial properties including antioxidant activity, anti-inflammation activity, cholesterol-lowering ability, and even anticancer activity. For these reasons, phytoalexin-enriched foods would be classified as functional foods. These phytoalexin-enriched functional foods would benefit the consumer by providing "health-enhanced" food choices and would also benefit many underutilized crops that may produce phytoalexins that may not have been considered to be beneficial health-promoting foods. PMID:19334749

Boue, Stephen M; Cleveland, Thomas E; Carter-Wientjes, Carol; Shih, Betty Y; Bhatnagar, Deepak; McLachlan, John M; Burow, Matthew E

2009-04-01

217

Selective Recovery of Enriched Uranium from Inorganic Wastes  

Microsoft Academic Search

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

Kimura

2003-01-01

218

Data on DOE's Uranium Enrichment Program  

SciTech Connect

This letter contains the answers to the following questions: What were DOE's expenditures for uranium enrichment research and development and pilot plant operations from 1970 to the present; What were DOE's expenditures for enrichment-related construction from 1970 to the present; What was the depreciation component of DOE's enrichment services price from 1970 to the present; and What are DOE's plans for recovering projected enrichment capital investments over the next 20 years. Questions dealing with the price TVA charges DOE for its electric power will be provided at a later date.

Not Available

1983-04-15

219

The oxygen enrichment of the galaxy  

SciTech Connect

Oxygen-to-hydrogen ratios are calculated for the 97 planetary nebulae for which there are sufficient data and for which the correction for unobserved ionization states is not too large. As a part of this study, emission-line fluxes are presented for 19 planetaries. The ratios are strongly correlated with population type. Almost all planetaries with absolute LSR radial velocity greater than about 85 km s/sup -1/ and distance from the galactic plane greater 1 kpc have low O/H; high values of O/H are confined to the galactic disk. The radial gradient within the disk is not easily discerned from the planetaries. An apparent gradient is seen because the planetaries with distances from the galactic center greater than about 11 kpc are dominantly halo objects with high velocity or large distance from the plane. The planetaries are divided into relative age groups which depend upon the nubular velocities, distances from the galactic plane, excitation levels, and He/H ratios. The mean O/H for each group increases with decreasing age. The available evidence shows that this effect is not due to nuclear processing in individual stars and is consequently an effect of galactic evolution. Galactic O/H has increased by a factor of between 5 and 10 from the time of the formation of the early halo to the present, consistent with earlier studies. The relative oxygen enrichment rate of the Galaxy is characterized by a large early increase from the old to the intermediate halo, followed by a smaller but steady relative enrichment rate among the identified age groups.

Kaler, J.B.

1980-07-01

220

Utilization of oxygen-enriched air in diesel engines: Fundamental considerations  

SciTech Connect

Utilization of oxygen-enriched air in diesel engines holds potential for low exhaust smoke and particulate emissions. The majority of the oxygen-enriched-air combustion-related studies so far are experimental in nature, where the observed results are understood on an overall basis. This paper deals with the fundamental considerations associated with the oxygen-enriched air-fuel combustion process to enhance understanding of the concept. The increase in adiabatic flame temperature, the composition of exhaust gases at equilibrium, and also the changes in thermodynamic and transport properties due to oxygen-enrichment of standard intake air are computed. The effects of oxygen-enrichment on fuel evaporation rate, ignition delay, and premixed burnt fraction are also evaluated. Appropriate changes in the ignition delay correlation to reflect the effects of oxygen-enrichment are proposed. The notion of oxygen-enrichment of standard intake air as being akin to leaning of the fuel-air mixture is refuted on the basis of the fundamentally different requirements for the oxygen-enriched combustion process.

Lahiri, D.; Mehta, P.S. [Indian Inst. of Tech., Madras (India); Poola, R.B.; Sekar, R. [Argonne National Lab., IL (United States)

1997-09-01

221

Gas-phase UF/sub 6/ enrichment monitor for enrichment plant safeguards  

SciTech Connect

An in-line enrichment monitor is being developed to provide real-time enrichment data for the gas-phase UF/sub 6/ feed stream of an enrichment plant. The nondestructive gamma-ray assay method can be used to determine the enrichment of natural UF/sub 6/ with a relative precision of better than 1% for a wide range of pressures.

Strittmatter, R.B.; Tape, J.W.

1980-03-01

222

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

Microsoft Academic Search

This work presents a liquid disposal monitoring originated from uranium enrichment process at Aramar Experimental Center from\\u000a 1990 to 1998. Assessment of uranium, fluorides, ammoniacal nitrogen, chemical oxygen demand, and pH measurements were made\\u000a in water samples and compared with results achieved in other countries, as North America and India. The liquid disposal evaluation,\\u000a generated by uranium enrichment process, showed

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

223

Enriching the hot circumgalactic medium  

NASA Astrophysics Data System (ADS)

Simple models of galaxy formation in a cold dark matter universe predict that massive galaxies are surrounded by a hot, quasi-hydrostatic circumgalactic corona of slowly cooling gas, predominantly accreted from the intergalactic medium (IGM). This prediction is borne out by the recent cosmological hydrodynamical simulations of Crain et al., which reproduce observed scaling relations between the X-ray and optical properties of nearby disc galaxies. Such coronae are metal poor, but observations of the X-ray emitting circumgalactic medium (CGM) of local galaxies typically indicate enrichment to near-solar iron abundance, potentially signalling a shortcoming in current models of galaxy formation. We show here that, while the hot CGM of galaxies formed in the simulations is typically metal poor in a mass-weighted sense, its X-ray luminosity-weighted metallicity is often close to solar. This bias arises because the soft X-ray emissivity of a typical ˜0.1 keV corona is dominated by collisionally excited metal ions that are synthesized in stars and recycled into the hot CGM. We find that these metals are ejected primarily by stars that form in situ to the main progenitor of the galaxy, rather than in satellites or external galaxies. The enrichment of the hot CGM therefore proceeds in an `inside-out' fashion throughout the assembly of the galaxy: metals are transported from the central galaxy by supernova-driven winds and convection over several Gyr, establishing a strong negative radial metallicity gradient. Whilst metal ions synthesized by stars are necessary to produce the X-ray emissivity that enables the hot CGM of isolated galaxies to be detected with current instrumentation, the electrons that collisionally excite them are equally important. Since our simulations indicate that the electron density of hot coronae is dominated by the metal-poor gas accreted from the IGM, we infer that the hot CGM observed via X-ray emission is the outcome of both hierarchical accretion and stellar recycling.

Crain, Robert A.; McCarthy, Ian G.; Schaye, Joop; Theuns, Tom; Frenk, Carlos S.

2013-07-01

224

Instrumental Enrichment with Low Achieving Adolescents.  

ERIC Educational Resources Information Center

|An assessment study was conducted on the effectiveness of a cognitive education program, Feuerstein's Instrumental Enrichment, in meeting the needs of a class of low achieving adolescents at a vocational school in Calgary, Canada. Fifteen students participated in an Instrumental Enrichment class for one 45 minute period five days a week over two…

Samuels, Marilyn; And Others

225

Improved tritium acid electrolysis enrichment system  

Microsoft Academic Search

A tritium acid electrolysis enrichment system is described for concentrating tritium in water samples. The parameters affecting tritium loss during electrolysis have been held constant so that a mathematical formula was developed for determining tritium enrichment. Consequently, different sample volumes may be electrolyzed simultaneously without the use of tritium standards for recovery determination. Data is presented for establishing the tritium

D. C. Bogen; J. Feldstein

1976-01-01

226

21 CFR 137.165 - Enriched flour.  

Code of Federal Regulations, 2010 CFR

...ingredients, prescribed for flour by § 137.105, except that...milligrams per pound. Enriched flour may be acidified with monocalcium...137.175 for phosphated flour, but, if insufficient additional...added to the food for enrichment purposes may be supplied by any...

2009-04-01

227

21 CFR 137.165 - Enriched flour.  

Code of Federal Regulations, 2010 CFR

...ingredients, prescribed for flour by § 137.105, except that...milligrams per pound. Enriched flour may be acidified with monocalcium...137.175 for phosphated flour, but, if insufficient additional...added to the food for enrichment purposes may be supplied by any...

2010-04-01

228

An Estimate of India's Uranium Enrichment Capacity  

Microsoft Academic Search

Although the existence of India's uranium enrichment program has been known for a while, there is little technical information on the program available in the public domain. Here, we try to estimate its capacity based on the assumption that it has succeeded in producing sufficient enriched uranium for the core of the prototype reactor for the nuclear submarine that India

M. V. Ramana

2004-01-01

229

Uranium enrichment and nuclear-weapon proliferation  

Microsoft Academic Search

The authors review state-of-the-art enrichment technology, and evaluate the impact of this technology on the proliferation problem. They place the technological development into the context of the economic and institutional environment that has evolved around the enrichment industry, and suggest some measures which might be taken to reduce the proliferation dangers inherent in the industry. They specifically note the world

A. S. Krass; P. Boskma; B. Elzen; W. A. Smit

1983-01-01

230

Uranium enrichment management review. Final report  

Microsoft Academic Search

The uranium enrichment enterprise of the US Department of Energy (DOE) provides enriched nuclear fuel for private and government utilities domestically and abroad. The enterprise, in effect, provides a commercial service and represents a signficant business operation within the US government: more than $1 billion in revenues annually and future capital expenditures estimated at several billions of dollars. As a

J. D. Ellett; W. B. Rieke; J. W. Simpson; P. E. Sullivan

1980-01-01

231

Lipid conversions during enrichment of Artemia  

Microsoft Academic Search

Artemia nauplii were enriched for 24 h with radiolabelled fatty acid ethyl esters and then starved for a subsequent period of 24 h. Analyses of the distribution of radioactivity in lipids from samples taken at the end of the enrichment period and after the subsequent starvation showed that the ethyl esters were readily converted into other lipid classes, mainly triacylglycerols,

Juan C Navarro; R. James Henderson; Lesley A McEvoy; Michael V Bell; Francisco Amat

1999-01-01

232

Enrichment of oxygen heavy isotopes during photosynthesis in phytoplankton.  

PubMed

Some of the oxygen produced during oxygenic photosynthesis is consumed but little is known about the extent of the processes involved. We measured the (17)O/(16)O and (18)O/(16)O ratios in O(2) produced by certain marine and freshwater phytoplankton representing important groups of primary producers. When the cells were performing photosynthesis under very low dissolved oxygen concentrations (< 3 ?M), we observed significant enrichment in both (18)O and (17)O with respect to the substrate water. The difference in ?(18)O between O(2) and water was about 4.5, 3, 5.5, and 7? in the diatom Phaeodactylum tricornutum, Nannochloropsis sp. (Eustigmatophyceae), the coccolithophore Emiliania huxleyi and the green alga Chlamydomonas reinhardtii, respectively. The difference in ?(17)O was about 0.52 that of ?(18)O. As explained, the observed enrichments most probably stem from considerable oxygen consumption during photosynthesis even when major O(2)-consuming reactions such as photorespiration were minimized. These enrichments increased linearly with rising O(2) levels but with different ?(17)O/?(18)O slopes for the various organisms, suggesting engagements of different O(2)-consuming reactions with rising O(2) levels. Consumption of O(2) may be important for energy dissipation during photosynthesis. The isotope enrichment observed here, not accounted for in earlier assessments, closes an important gap in our understanding of the difference between the isotopic compositions of atmospheric oxygen and that of seawater, i.e., the Dole effect. PMID:20054712

Eisenstadt, Doron; Barkan, Eugeni; Luz, Boaz; Kaplan, Aaron

2010-02-01

233

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

234

Parametric study on the enrichment of immunoglobulin from milk by foam fractionation.  

PubMed

Foam fractionation is a promising method for separation and concentration of biochemicals. It is simple, easily scalable, inexpensive, and environment friendly. Foam fractionation thus represents an alternative to the traditional methods used for immunoglobulin enrichment. However, little, if any, literature exists documenting the utilization of foam fractionation in the enrichment of immunoglobulins. Milk were utilized as an immunoglobulin source to serve as examples of a real system in this study. The investigation examined the effects of varying five different process parameters: the initial pH value, the initial concentration of immunoglobulin, the nitrogen flow rate, the column height, and the foaming time. Experimental results demonstrated that immunoglobulin could effectively be enriched from milk by foam fractionation. The maximum enrichment ratio with pretreatment (using pH 4.6 precipitation) was 6.30 along with a more than 92 % recovery for IgG and an enrichment ratio of 5.1 with 85 % recovery for IgM. PMID:23709288

Chen, Yen-Chih; Parlar, Harun

2013-05-25

235

Mortality among uranium enrichment workers  

SciTech Connect

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

Brown, D.P.; Bloom, T.

1987-01-01

236

Enrichment of oxygen heavy isotopes during photosynthesis in phytoplankton  

Microsoft Academic Search

Some of the oxygen produced during oxygenic photosynthesis is consumed but little is known about the extent of the processes\\u000a involved. We measured the 17O\\/16O and 18O\\/16O ratios in O2 produced by certain marine and freshwater phytoplankton representing important groups of primary producers. When the cells\\u000a were performing photosynthesis under very low dissolved oxygen concentrations (<3 ?M), we observed significant enrichment

Doron Eisenstadt; Eugeni Barkan; Boaz Luz; Aaron Kaplan

2010-01-01

237

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

238

Robotic design for an automated uranium solution enrichment system  

Microsoft Academic Search

A method to automate solution enrichment analysis by gamma-ray spectroscopy is being developed at Los Alamos National Laboratory. Both passive and x-ray fluorescence (XRF) analyses will be remotely performed to determine the amounts of ²³⁵U and total uranium in sample containers. A commercial laboratory robot will be used to process up to 40 batch and 8 priority samples in an

E. C. Horley; T. Beugelsdijk; R. S. Biddle; L. E. Bronisz; W. J. Hansen; T. K. Li; T. E. Sampson; G. Walton

1990-01-01

239

Enrichment behavior and transport mechanism of soil-bound PAHs during rainfall-runoff events.  

PubMed

Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation. PMID:22885221

Zheng, Yi; Luo, Xiaolin; Zhang, Wei; Wu, Bin; Han, Feng; Lin, Zhongrong; Wang, Xuejun

2012-08-10

240

21 CFR 136.115 - Enriched bread, rolls, and buns.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Enriched bread, rolls, and buns. 136.115 Section...Bakery Products § 136.115 Enriched bread, rolls, and buns. (a) Each of the foods enriched bread, enriched rolls, and enriched...

2010-04-01

241

21 CFR 136.115 - Enriched bread, rolls, and buns.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Enriched bread, rolls, and buns. 136.115 Section...Bakery Products § 136.115 Enriched bread, rolls, and buns. (a) Each of the foods enriched bread, enriched rolls, and enriched...

2009-04-01

242

Assuaging Nuclear Energy Risks: The Angarsk International Uranium Enrichment Center  

Microsoft Academic Search

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

Astasia Myers; Astasia

2011-01-01

243

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

SciTech Connect

The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 years. 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 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; SIO 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 capabilities 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.

Aaron, W.S.; Tracy, J.G.; Collins, E.D.

1996-10-01

244

Comparison of Different Phosphopeptide Enrichment Strategies In Phosphoprotein Analysis  

PubMed Central

Protein phosphorylation and dephosphorylation constitutes one of the reversible posttranslational mechanisms that control several cellular processes including gene expression, signal transduction, cell cycle, apoptosis and cytoskeletal regulation. It is estimated that at least one third of the total proteins are phosphorylated at any given time point. Due to its dynamic nature, stoichiometry of phosphorylation is usually low. This presents a challenge for mass spectrometry analysis of phosphoproteins and phosphopeptides. To overcome the challenge, a phosphoprotein/phosphopeptide enrichment step becomes necessary prior to mass spectrometry analysis. There are several commercial affinity resins that provide different metal, metal oxide or phosphate binding tags to selectively enrich phosphopeptides. The goal of this work was to develop an effectively methodology for phosphopeptide enrichment and phosphorylation site mapping through comparing the capabilities of different TiO2, ZrO2 and Phos-tag resins. The protocol for each media was tested with ?-casein to determine the efficiency of the resins. Then, we used a purified and in vitro phosphorylated SnRK to optimize the protocol for detecting low phosphorylation stoichiometry in biological samples. The protein samples (SnRK and SnRK-pho) were run in a gel. After Coomassie staining and in-gel digestion, the phosphopeptided were enriched using different media. All phosphopeptide samples were run on a nanoflow UPLC coupled to a LTQ-Orbitrap mass spectrometer. Multi-stage activation was used to trigger fragmentation when a neutral loss of 98 occurs in the peptides. The results showed that the methods have different selectivity and yield depending on the media used for the enrichment.

Zhu, M.; Diaz, C.; Chen, S.; Silva-Sanchez, Cecilia

2012-01-01

245

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

246

Uranium enrichment and nuclear-weapon proliferation  

SciTech Connect

The authors review state-of-the-art enrichment technology, and evaluate the impact of this technology on the proliferation problem. They place the technological development into the context of the economic and institutional environment that has evolved around the enrichment industry, and suggest some measures which might be taken to reduce the proliferation dangers inherent in the industry. They specifically note the world excess of supply over demand which, coupled with the refusal of a number of countries with enrichment capability to sign the Non-Proliferation Treaty, intensifies the weapons risk. 336 references, 52 figures, 20 tables.

Krass, A.S.; Boskma, P.; Elzen, B.; Smit, W.A.

1983-01-01

247

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

248

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2010 CFR

...Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched culture medium is a device that consists primarily...The device consists of a relatively simple basal medium enriched by the addition of such...

2009-04-01

249

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2010 CFR

...Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched culture medium is a device that consists primarily...The device consists of a relatively simple basal medium enriched by the addition of such...

2010-04-01

250

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Inerting, enriching, and diluting systems...Vapor Control Systems § 154.824 Inerting, enriching, and diluting systems. (a) A vapor control system which uses inerting, enriching, or diluting gas must...

2009-07-01

251

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Inerting, enriching, and diluting systems...Vapor Control Systems § 154.824 Inerting, enriching, and diluting systems. (a) A vapor control system which uses inerting, enriching, or diluting gas must...

2010-07-01

252

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

PubMed

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

Morgenstern, Uwe; Taylor, Claude B

2009-06-01

253

N2O emissions from a nitrogen-enriched river  

USGS Publications Warehouse

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

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

1999-01-01

254

Ensuring multimedia content enrichment by means of data hiding techniques  

NASA Astrophysics Data System (ADS)

Nowadays, a large variety of emerging applications (clickable, video, interactive high definition television, intelligent interfaces) do not only process the multimedia content (audio, video, 3D,...) but some additional data directly connected to it, as well. This enrichment information is usuall transmitted and stored as an additional independent stream (metadata). Such an approach can be restrictive sometimes, mainly for the networks/application with strict bandwidth and/or protocol constraints. An alternative solution is advanced and discussed in this paper. The principle consists in transmitting the metadata via in-band channels obtained by means of data hiding (watermarking) techniques. The challenge is to design data hiding techniques reaching the trade off among transparency (the enrichment process should not alter the perceptual quality of the host media), robustness (possibility to recover the metadata at the end user even when the high distortions occur through the channel) and data payload (the amount of metadata which can be inserted). The paper investigates the feasibility of such techniques by evaluating the maximal data payload (the watermarking capacity) under given robustness and transparency constraints. The results are compared to the resources needed by some existing enrichment applications. The experiments are carried out in collaboration with the French mobile service operator SFR (Vodafone Group) and consider video sequences watermarked in the DWT domain.

Mitrea, M.; Duta, S.; Zaharia, T.; Pr"teux, F.

2006-11-01

255

Measurement of uranium enrichment for gaseous uranium at low pressure  

SciTech Connect

X-ray fluoresence determines the amount of total uranium present in gaseous UF/sub 6/ inside cascade header pipes of a uranium centrifuge enrichment facility. A highly collimated source, highly collimated detector, and a very rigid, reproducible geometry are required. Two measurements of the 185.7-keV gamma ray from /sup 235/U using two collimators determine the amount of /sup 235/U present only in the gas phase. The ratio of the gas-only /sup 235/U signal to the total uranium gas-only signal is directly proportional to the enrichment of the process UF/sub 6/ gas. This measurement technique is independent of the deposit that forms on a surface in contact with UF/sub 6/. This measurement technique is independent of the pressure of the gaseous UF/sub 6/. This technique has the required sensitivity to determine whether the process gas is of uranium enrichment less than or equal to 20% or >20%. 6 refs., 4 figs., 4 tabs.

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

1985-01-01

256

Fire Extinguishment in Oxygen Enriched Atmospheres.  

National Technical Information Service (NTIS)

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 chemicall...

A. F. Robertson M. W. Rappaport

1973-01-01

257

Self-disproportionation of Enantiomers of Enantiomerically Enriched Compounds.  

PubMed

This review describes self-disproportionation of enantiomers (SDE) of non-racemic mixtures, subjected to distillation, sublimation, or chromatography on achiral stationary phase using achiral eluent, which leads to the substantial enantiomeric enrichment and corresponding depletion in different fractions, as compared to the enantiomeric composition of the starting material. This phenomenon is of a very general nature as SDE has been reported for different classes of chiral organic compounds bearing various functional groups and possessing diverse elements of chirality. The literature data discussed in this review clearly suggests that SDE is typical for enantiomerically enriched chiral organic compounds and special care should always be taken in evaluation of the stereochemical outcome of enantioselective reactions as well as determination of enantiomeric ratios of non-racemic mixtures of natural products after any purification process. The role of molecular association of enantiomers on the magnitude and preparative efficiency of SDE, as a new, nonconventional method for enantiomerc purifications, is emphasized and discussed. PMID:23605252

Sorochinsky, Alexander E; Soloshonok, Vadim A

2013-04-19

258

Silver surface enrichment in ancient coins studied by micro-PIXE  

NASA Astrophysics Data System (ADS)

The surface enrichment of archeological silver-copper alloys, either intentional or due to corrosion processes, has been known for many years. The most used non-destructive techniques, such as particle-induced X-ray emission (PIXE) and X-ray fluorescence (XRF) are surface techniques, with penetration depths typically ranging from a few microns to a few tens of microns. Therefore, these techniques could produce results which are not representative of the bulk composition of the alloy.In order to gain insight into the silver enrichment process and the effects on the data obtained with these techniques, a set of silver roman denarii were cross sectioned and analyzed at the Centro Nacional de Aceleradores micro-PIXE facility. Elemental maps show silver surface enriched layers up to 250 ?m thick. Besides, silver-enriched surface layers are not found for alloys with 96-98 wt.% Ag.

Ager, F. J.; Moreno-Suárez, A. I.; Scrivano, S.; Ortega-Feliu, I.; Gómez-Tubío, B.; Respaldiza, M. A.

2013-07-01

259

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

260

Community response to enrichment is highly sensitive to model structure  

PubMed Central

Biologists use mathematical functions to model, understand and predict nature. For most biological processes, however, the exact analytical form is not known. This is also true for one of the most basic life processes: the uptake of food or resources. We show that the use of several nearly indistinguishable functions, which can serve as phenomenological descriptors of resource uptake, may lead to alarmingly different dynamical behaviour in a simple community model. More specifically, we demonstrate that the degree of resource enrichment needed to destabilize the community dynamics depends critically on the mathematical nature of the uptake function.

Fussmann, Gregor F; Blasius, Bernd

2004-01-01

261

Using Social Media for Ontology Enrichment  

Microsoft Academic Search

\\u000a In order to support informal learning, we complement the formal knowledge represented by ontologies developed by domain experts\\u000a with the informal knowledge emerging from social tagging. To this end, we have developed an ontology enrichment pipeline that\\u000a can automatically enrich a domain ontology using: data extracted by a crawler from social media applications, similarity measures,\\u000a the DBpedia knowledge base, a

Paola Monachesi; Thomas Markus

2010-01-01

262

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

263

Carbon dioxide enrichment of greenhouse crops  

SciTech Connect

This volume contains the following on these major topics of physiology, yield and economics: Fixation of Inorganic Carbon in Plant Cells. Effects of CO/sub 2/ Enrichment on Photosynthesis of C/sub 3/ Plants. Effects of CO/sub 2/ Concentration on Photosynthesis and Respiration of C/sub 4/ and CAM Plants. Effects of CO/sub 2/ Concentration on Composition, Anatomy, and Morphology of Plants. Stimulation of Growth and Yield Under Environmental Restraints. Woody Plant Reactions to CO/sub 2/ Enrichment. Influence of the CO/sub 2/ Content of the Ambient Air on Stomatal Conductance and CO/sub 2/ Concentration in Leaves. Influence of Elevated CO/sub 2/ on Crop Yield. Fertilization of Carnations and Some Other Flower Crops. CO/sub 2/ Enrichment for Greenhouse Rose Production. CO/sub 2/ Enrichment of Tomato Crops. CO/sub 2/ Enrichment Duration and Heating Credit as Determined by Climate. Economics of CO/sub 2/ Enrichment in Greenhouses. Units Conversion. Currency Exchange Rates.

Enoch, H.Z.; Kimball, B.A.

1986-01-01

264

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

Microsoft Academic Search

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

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

265

Enrichment of anammox bacteria from marine environment for the construction of a bioremediation reactor  

Microsoft Academic Search

In the global ocean nitrogen cycle, the anaerobic ammonium-oxidizing (anammox) process is recognized as important. In this\\u000a study, we established an enrichment culture of marine anammox bacteria (MAB) in a column-type reactor. The reactor, which\\u000a included a porous polyester non-woven fabric that had been placed at the sea floor in advance for enrichment, was continuously\\u000a fed with NH4Cl and NaNO2

Jun Nakajima; Makiko Sakka; Tetsuya Kimura; Kenji Furukawa; Kazuo Sakka

2008-01-01

266

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

Microsoft Academic Search

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

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

2009-01-01

267

Test Operation of Oxygen-Enriched Incinerator for Wastes From Nuclear Fuel Fabrication Facility  

Microsoft Academic Search

The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of

J.-G. Kim; H. c C. Yang; G.-I. Park; I.-T. Kim; J.-K. Kim

2002-01-01

268

Relationship between isotopic uranium activities and total uranium at various uranium enrichments  

Microsoft Academic Search

There is often a need to calculate isotopic uranium activities from total uranium mass or gamma spectrometry measurement data.\\u000a This calculation is based on a model of the relationship of the234U activity to that of235U since both are enriched together in the normal gaseous diffusion enrichment process. This paper presents equations for calculating\\u000a these activities that have been developed from

T. L. Rucker; C. M. Johnson

1998-01-01

269

Enchanced gas separation process  

Microsoft Academic Search

A process for the enhanced separation of gases is described comprising: (a) contacting a feed gas stream at an elevated pressure with a permeable membrane capable of selectively permeating a first component thereof, thereby obtaining a first component enriched, second component depleted permeate portion of the feed stream at a reduced pressure, and a second component enriched, first component depleted

Doshi

1987-01-01

270

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

271

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

Code of Federal Regulations, 2013 CFR

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

2013-01-01

272

Processing  

Microsoft Academic Search

In support of a model of language comprehension in which pragmatic biases are integrated with syntactic processing, we show that expectations about upcoming discourse continuations inuence the resolution of local structural ambiguity. An o-line sentence-completion study and an on- line self-paced reading study examined readers' expectations for high\\/low relative clause attachments following implicit-causality and non-implicit- causality verbs (John detests\\/babysits the

Hannah Rohde; Roger Levy; Andrew Kehler

273

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

2007-01-30

274

Availability of enriched isotopic materials used for accelerator targets - Present and future  

NASA Astrophysics Data System (ADS)

The availability of a broad spectrum of highly enriched stable isotopes is vitally important for the fabrication of nuclear targets for basic and applied research. The present separation effort at the Oak Ridge National Laboratory is insufficient to maintain equilibrium for the stable isotope inventory. The current technology that is being applied in the electromagnetic isotope separation process to minimize the stable isotope depletion rate is discussed. Three alternative separation processes, gas centrifugation, plasma cyclotron resonance separation, and laser separation, are evaluated as candidates to augment the present stable isotopes separation facility. The applicability of each process to the isotopic enrichment of the calutron feed material and to the selective production of isotopes is determined. The process energy demands are compared to those of the existing facilities. The isotopic enrichment of the feed material prior to a first pass through the calutrons can result in significant savings in energy and cost.

Tracy, J. G.; Terry, J. W.

1985-05-01

275

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

276

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

PubMed

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

Fleischer, Robert L

2008-03-01

277

Direct enrichment of perchlorate-reducing microbial community for efficient electroactive perchlorate reduction in biocathodes.  

PubMed

Biological reduction of perchlorate (ClO4 (-)) has emerged as a promising solution for the removal of perchlorate in contaminated water and soils. In this work, we demonstrate a simple process to enrich perchlorate-reducing microbial communities separately using acetate as electron donor and the municipal aerobic membrane bioreactor sludge as inoculum. Inoculation of cathodes in microbial fuel cells (MFCs) with these enrichments, and further electrochemical enrichment at constant resistance operation of the MFCs, led to perchlorate-reducing biocathodes with peak reduction rates of 0.095 mM/day (2 mg/m(2)/day). Analysis of the microbial diversity of perchlorate-reducing biocathodes using PCR-DGGE revealed unique community profiles when compared to the denitrifying biocathode communities. More importantly, the total time taken for enrichment of the electroactive communities was reduced from several months reported previously in literature to less than a month in this work. PMID:23925794

Mieseler, Maren; Atiyeh, Mays N; Hernandez, Hector H; Ahmad, Farrukh

2013-08-08

278

Information on DOE's costing and pricing of uranium enrichment services  

SciTech Connect

The Department of Energy (DOE) provides domestic and foreign customers with enriched uranium for use as commercial nuclear power reactor fuel. Competition from foreign enrichment suppliers and from a secondary market of surplus enriched uranium has led to a significant decline in DOE's enrichment sales. During a March 1, 1984, hearing before the subcommittee, GAO commented on a number of DOE initiatives and proposals designed to improve the uranium enrichment program's viability. This report addresses topics raised during that hearing and presents information on (1) DOE's historic pricing policy and practices associated with providing uranium enrichment services, (2) the historical annual enrichment costs and prices, (3) the accumulated profit or loss reported in the enrichment program's financial statements, (4) the implications for recovering DOE's cost of providing enrichment services at the $135 ceiling price provision contained in the new enrichment services contract, and (5) details on GAO's efforts to obtain information from DOE on the ceiling price provision.

Not Available

1984-04-25

279

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.

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

2009-01-01

280

Uranium enrichment: heading for the abyss  

SciTech Connect

This article discusses the federal government's $2.3 billion a year business enriching uranium for nuclear power plants which is heading toward a major crisis. Due to miscalculations by the Department of Energy, it is caught with billions of dollars of construction in progress just as projected demand for enriched uranium is decreasing. At the center of the controversy is the Gas Centrifuge Plant at Portsmouth, Ohio - estimated to cost $10 billion dollars. A review of how DOE got into this situation and how they plan to solve it is presented.

Norman, C.

1983-08-19

281

Enriched uranium processing with 7-1\\/2% TBP  

Microsoft Academic Search

The 7-1\\/2% TBP flowsheet gives adequate recovery of uranium and neptunium or plutonium, with reduced waste volume as compared to the prior aluminum-salted 3-1\\/2% TBP flowsheet. Decontamination from fission products is sensitive to numerous variables, including aluminum nitrate concentration in the feed, impeller speeds, and prior treatment of the fuel solution in head end operations. The impeller speed in the

D. A. Orth; W. H. Martin; C. E. Pickett

1983-01-01

282

Bringing the community in: partnerships for aging enrichment.  

PubMed

Aging enrichment of undergraduate social work curricula ensures that program graduates will be prepared to practice with older adults. This article reports the results of focus group research that was designed to engage social workers from community agencies serving older adults in preparing students to become "aging-savvy" social workers. The workers highlighted the importance of wide-ranging exposure to older adults, the changing needs of older adults, and the importance of increasing students' comfort with self-determination. These findings informed the program's ongoing curricular transformation process through the incorporation of new assignments that enabled increased contact with older adults in a variety of settings. PMID:17210539

Swanson Ernst, Joy; Sowbel, Lynda

2007-01-01

283

Construction et enrichissement automatique d'ontologie à partir de ressources externes  

Microsoft Academic Search

Automatic construction of ontologies from text is generally based on\\u000aretrieving text content. For a much more rich ontology we extend these\\u000aapproaches by taking into account the document structure and some external\\u000aresources (like thesaurus of indexing terms of near domain). In this paper we\\u000adescribe how these external resources are at first analyzed and then exploited.\\u000aThis method

Eric Kergosien; Mouna Kamel; Christian Sallaberry; Marie-Noëlle Bessagnet; Nathalie Aussenac- Gilles; Mauro Gaio

2010-01-01

284

Une approche micro-macro pour le suivi de fissure avec enrichissement local  

Microsoft Academic Search

Dans cet article, une stratégie de calcul multiéchelle pour le suivi de fissure est pré-sentée. Cette stratégie a pour objectif de séparer les effets locaux des effets globaux afin de garder un maillage macro inchangé au cours de la propagation tout en permettant l'utilisation d'une description fine uniquement où cela est nécessaire. Deux points sont discutés : le premier est

Pierre-Alain Guidault; Olivier Allix; Laurent Champagney; Christian Cornuault

2006-01-01

285

CUE (CULTURE, UNDERSTANDING, ENRICHMENT)--HOME ECONOMICS.  

ERIC Educational Resources Information Center

THIS PUBLICATION IS A TEACHING GUIDE TO PROVIDE GUIDANCE FOR INTEGRATING CAREFULLY SELECTED AUDIOVISUAL ITEMS INTO EXISTING NINTH-GRADE CURRICULUMS IN HOME ECONOMICS. IT IS ONE OF FIVE GUIDES PREPARED FOR USE IN PROJECT CUE, AN EXPERIMENTAL PROGRAM DESIGNED TO INCREASE CULTURAL UNDERSTANDING AND ENRICHMENT IN THE EDUCATIONAL PROGRAMS OF HIGH…

BROWN, ROBERT M.; AND OTHERS

286

Enriching a Child's Literacy Environment (ECLE).  

ERIC Educational Resources Information Center

|The Enriching a Child's Literacy Environment (ECLE) program was designed to establish a model for teaching parents, teachers, and other care providers how to develop the oral language, thinking abilities and motor skills of young children (ages six months to three years). ECLE trainers instruct the parents or other care providers by first…

Reid, Ethna R.

287

Enrichment for Nonhuman Primates: Squirrel Monkeys (Saimiri).  

National Technical Information Service (NTIS)

This book serves as an introduction to the basic behavior and environmental enrichment of a specific species of nonhuman primates that are more commonly used in education, research and entertainment. In many ways, this book is meant to be a how to manual;...

A. M. Schuler C. R. Abee

2005-01-01

288

Anammox enrichment from different conventional sludges  

Microsoft Academic Search

Three sets of sequencing batch reactor (SBR) were used for Anammox enrichment from conventional sludges including upflow anaerobic sludge blanket, activated sludge, and anaerobic digestion sludge. After four months of operation, the Anammox activity occurred in all reactors allowing continuous removal of ammonium and nitrite. The morphology of the cultivated Anammox sludge was observed using scanning electron microscope. The photographs

Nutchanat Chamchoi; Suwanchai Nitisoravut

2007-01-01

289

Anammox Organisms: Enrichment, Cultivation, and Environmental Analysis  

Microsoft Academic Search

Anaerobic ammonium oxidation (anammox) is the microbial oxidation of ammonium with nitrite to dinitrogen gas under strict anoxic conditions mediated by planctomycete?like bacteria. Anammox is not only important in the oceanic nitrogen cycle, but can also contribute substantially to nitrogen removal in municipal and industrial wastewater treatment. This chapter addresses the enrichment and cultivation of anammox bacteria in a sequencing

Mike Jetten; Markus Schmid; Jaap Sinninghe Damsté; Marc Strous

2005-01-01

290

Structured Enrichment (SE) with Couples and Families.  

ERIC Educational Resources Information Center

|Summarizes and reviews the past decade of work to develop Structured Enrichment (SE) programs. Discusses four major representative functions to indicate the testability of SE. Considers further research on its comparative usefulness, expansion to clinical populations, and the testing of component skills. (NRB)|

L'Abate, Luciano

1985-01-01

291

The Effects of Early Language Enrichment  

ERIC Educational Resources Information Center

|Over two decades, six studies evaluated the effects of a home-based early language program on the development of 101 infants. Parents engaged in enrichment activities with their infants over a one-year period that began when the infants were between three and 13 months of age. Participants from families with varied levels of education were…

Fowler, William; Ogston, Karen; Roberts, Gloria; Swenson, Amy

2006-01-01

292

DOE and the United States enrichment market  

Microsoft Academic Search

The US Department of Energy (DOE) and its predecessors have exerted a predominant influence in the uranium enrichment services industry since 1969, when it began to sell its services to private industry under a Requirement-Type Contract (RTC). After almost 25 years of providing these services to utilities throughout the world, DOE is now preparing to hand over responsibility to the

Rutkowski

1993-01-01

293

On Feuerstein's Instrumental Enrichment: A Collection.  

ERIC Educational Resources Information Center

|On the premise that all children can learn, Reuven Feuerstein developed a classroom curriculum designed to build the cognitive functions of students diagnosed by others as incapable of learning. His program, Instrumental Enrichment (IE), provides students with the concepts, skills, strategies, operations, and techniques necessary to become…

Ben-Hur, Meir, Ed.

294

Prototyping Naturalistic Enrichment Features: A Case Study  

Microsoft Academic Search

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

Greg Whittaker; Margaret Whittaker; Jon Coe

295

ENRICHED-URANIUM HYDRIDE CRITICAL ASSEMBLIES  

Microsoft Academic Search

Assemblies considered consist of approximate spheres of enriched-uranium ; hydride composition (approximating UHâ) in 8-in. thick normal uranium and ; nickel reflectors and in a uranium reflector with nickel liner. Data are of the ; following types- (1) critical sizes, (2) values of Rossi alpha in the ; neighborhood of delayed critical, (3) activation rates of various internal ; neutron

G. A. Linenberger; J. D. Orndoff; H. C. Paxton

1960-01-01

296

Divertor Enrichment Modeling for DIII--D  

NASA Astrophysics Data System (ADS)

Helium and neon enrichment in the DIII--D divertor has been examined with the b2.5 code. The dependence of enrichment on plasma edge conditions and on divertor plate recycling coefficients has been studied and comparisons with two-point models shows that, while such models are adequate to represent the behavior of the midplane-divertor plate pressure drop for attached divertor cases, they fail to describe enrichment and do not well describe the pressure drop under detached conditions. Since the b2.5 code has a simplified model for He and Ne atomic physics, especially under detached conditions, we have begun work with the B2-Eirene divertor code [developed by KFA-Juelich, IPP-Garching, ITER GCC], which implicitly couples the 3D Eirene neutrals solution with the evolving b2 solution. The code is being applied to model the observed enrichment during He exhaust experiments under attached divertor conditions, and for partially detached divertor discharges in which He puffing was used, but without exhaust. Comparisons with edge CER, baffle measurements and Multichord Divertor Spectroscopy are used to constrain the model. A comparison of He and Ne retention is part of the study, which uses the Asdex-Ugrade ELMy H--mode transport model.

Owen, L.; Hogan, J.; Wade, M. R.; Isler, R. C.; Maingi, R.; Coster, D.

1996-11-01

297

Enrichment Education: Key to NCLEX Success.  

ERIC Educational Resources Information Center

|A concomitant decrease in test scores and major change in the composition of the student body was dealt with by the College of Nursing at the State University of New York through the Nursing Education Success Plan. The plan addresses student preparation for the National Council Licensure Exam (NCLEX), curriculum revision, remediation/enrichment

Wolahan, Caryle G. Hussey; Wieczorek, Rita Reis

1991-01-01

298

Query enrichment for web-query classification  

Microsoft Academic Search

Web-search queries are typically short and ambiguous. To classify these queries into certain target categories is a difficult but important problem. In this article, we present a new technique called query enrichment, which takes a short query and maps it to intermediate objects. Based on the collected intermediate objects, the query is then mapped to target categories. To build the

Dou Shen; Rong Pan; Jian-tao Sun; Jeffrey Junfeng Pan; Kangheng Wu; Jie Yin; Qiang Yang

2006-01-01

299

CUE (CULTURE, UNDERSTANDING, ENRICHMENT)--INDUSTRIAL ARTS.  

ERIC Educational Resources Information Center

THIS PUBLICATION IS A TEACHING GUIDE TO PROVIDE GUIDANCE FOR INTEGRATING CAREFULLY SELECTED AUDIOVISUAL ITEMS INTO EXISTING NINTH-GRADE CURRICULUMS IN INDUSTRIAL ARTS. IT IS ONE OF FIVE GUIDES PREPARED FOR USE IN PROJECT CUE, AN EXPERIMENTAL PROGRAM DESIGNED TO INCREASE CULTURAL UNDERSTANDING AND ENRICHMENT IN THE EDUCATIONAL PROGRAMS OF HIGH…

BROWN, ROBERT M.; AND OTHERS

300

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

301

CUE (CULTURE, UNDERSTANDING, ENRICHMENT)--SCIENCE.  

ERIC Educational Resources Information Center

|THIS PUBLICATION IS A TEACHING GUIDE TO PROVIDE GUIDANCE FOR INTEGRATING CAREFULLY SELECTED AUDIOVISUAL ITEMS INTO EXISTING NINTH-GRADE CURRICULUMS IN SCIENCE. IT IS ONE OF FIVE GUIDES PREPARED FOR USE IN PROJECT CUE, AN EXPERIMENTAL PROGRAM DESIGNED TO INCREASE CULTURAL UNDERSTANDING AND ENRICHMENT IN THE EDUCATIONAL PROGRAMS OF HIGH SCHOOLS.…

BROWN, ROBERT M.; AND OTHERS

302

Using Synchronous Technology to Enrich Student Learning  

ERIC Educational Resources Information Center

|To explore the potential applications of synchronous technology to enrich student learning, faculty members from an American regional state university and a Chinese regional university collaborated to find appropriate ways to integrate synchronous technology (e.g., Adobe Connect) into an educational technology program in the American university…

Wang, Charles Xiaoxue; Jaeger, David; Liu, Jinxia; Guo, Xiaoning; Xie, Nan

2013-01-01

303

Steroid hormone enrichment of Artemia nauplii  

Microsoft Academic Search

Steroid treatment of fish species prior to sexual differentiation changes the developing gonad. Administration of steroids via the diet produces a higher percentage of sexually inverted individuals than other methods. However, hormone-enriched commercial diets are unsuitable for larvae of fish species, such as yellow perch, that require live diets (such as Artemia) during the time of sexual differentiation. Steroids have

A. B Stewart; A. V Spicer; E. K Inskeep; R. A Dailey

2001-01-01

304

Computer Enrichment Handbook [and] Supplement A.  

ERIC Educational Resources Information Center

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

White, Bonnie Roe, Ed.; And Others

305

First private US enrichment plant: LES  

SciTech Connect

Louisiana Energy Services L.P. (LES) was established March 31, 1990. The general partners are wholly owned subsidiaries of Duke Power and Northern States Power, Fluor-Daniel International, and Urenco (a European consortium with enrichment plants in the United Kingdom, the Federal Republic of Germany, and the Netherlands). The partnership will build the first privately owned uranium enrichment facility in the US and commence operation at the end of 1995. It will have a capacity of 1,500,000 separative work units (SWU) per year. LEW has applied for its license from the Nuclear Regulatory Commission (NRC), this being the first licensing action for an enrichment facility in the US and the first major nuclear facility application in the US in more than a decade. The initial reception of US utilities to LES marketing efforts has been favorable. Many see LES as a desirable competitive factor in a marketplace dominated by the DOE and subjected to many factors peculiar to government. The 15% share of domestic usage targeted by LES is not enough to threaten DOE viability and provides an impetus for privatization of DOE enrichment enterprise. Such privatization is favored by most participants in the US nuclear industry, including LES.

Arnold, W.H.

1991-11-01

306

American Indian Enrichment Activities. Mini-Review.  

ERIC Educational Resources Information Center

|Focusing on American Indians, this annotated bibliography covers a variety of resources for enriching multicultural education in the elementary classroom and includes limited information about Mexican Americans, Blacks, and other cultural groups. Each of the 26 entries provides a descriptive annotation and indicates where the material can be…

Kosnick, Sally

307

Recommendations based on semantically enriched museum collections  

Microsoft Academic Search

This article presents the CHIP demonstrator 1 for providing personalized access to digital museum col- lections. It consists of three main components: Art Recommender, Tour Wizard, and Mobile Tour Guide. Based on the semantically enriched Rijksmuseum Amsterdam 2 collection, we show how Semantic Web technologies can be deployed to (partially) solve three important challenges for recommender systems applied in an

Yiwen Wang; Natalia Stash; Lora Aroyo; Peter Gorgels; Lloyd Rutledge; Guus Schreiber

2008-01-01

308

Books to Expand and Enrich Experiences.  

ERIC Educational Resources Information Center

|Books are briefly described that parents can read and discuss with their children to enrich travel and cultural activities. Books on the nation's capital city, the Liberty Bell, the Statue of Liberty, architecture, zoos, dinosaurs, and other subjects are included. (PP)|

Winfield, Evelyn T.

1983-01-01

309

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

310

Heating and Chemical Enrichment in the Core of the Antlia Cluster  

NASA Astrophysics Data System (ADS)

The dynamical processes responsible for heating and chemical enrichment of the ICM depend upon the environment and thus the cluster's evolutionary stage. These processes create distinct X-ray signatures in the hot cluster gas. We use a 53 ks XMM exposure of the core of the Antlia cluster, a galaxy cluster in an intermediate merger stage without a cool core, to study the transport of energy and metals throughout the ICM. We construct density, temperature, pressure, entropy and abundance maps to identify gas motions and heat flows, relate these motions to metal abundance ratios and gradients, and test simple models for chemical enrichment and heating of the Antlia cluster gas.

Hawley, William

2011-08-01

311

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

PubMed

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

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

2011-08-04

312

Evaluation of enrichment techniques for mass spectrometry: identification of tyrosine phosphoproteins in cancer cells.  

PubMed

Phosphorylation of tyrosine residues by protein tyrosine kinases mediates numerous cellular processes. Deregulated tyrosine phosphorylation underlies constitutive activation of signaling pathways leading to oncogenesis. Analytical techniques for evaluation of the global phosphoproteome level are challenging and can be improved on to enhance yields. Here, we evaluated several approaches to enrich for tyrosine phosphoproteins in cancer cells for subsequent liquid chromatography-tandem mass spectrometry analysis using lysates from SU-DHL-1 cells, which express the nucleophosmin-anaplastic lymphoma kinase tyrosine kinase as a model system. Cells were grown in the presence or absence of the phosphatase inhibitor sodium orthovanadate, and tyrosine phosphoproteins were subsequently enriched by immunoprecipitation or immunoaffinity chromatography and protein identification performed by liquid chromatography-tandem mass spectrometry. Our results show that sodium orthovanadate improves enrichment and thus detection of tyrosine phosphoproteins. Immunoprecipitation of tyrosine phosphoproteins using two different antiphosphotyrosine antibodies increased the number of protein identifications. Finally, peptides from proteins enriched by immunoprecipitation were more abundant (n=338) than those enriched by immunoaffinity chromatography (n=138), and relatively few proteins were found in common (n=43). Our data demonstrate the utility of an enrichment strategy for the mass spectrometry-based identification of tyrosine phosphoproteins and show the advantage of complementary techniques for greater protein identification. PMID:17384208

Schumacher, Jonathan A; Crockett, David K; Elenitoba-Johnson, Kojo S J; Lim, Megan S

2007-04-01

313

75 FR 52996 - Areva Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of Atomic Safety and...  

Federal Register 2010, 2011, 2012, 2013

...Rock Enrichment Facility); Notice of Atomic Safety and Licensing Board Reconstitution...2.313(c) and 2.321(b), the Atomic Safety and Licensing Board (Board) in...Hawkens, Chief Administrative Judge, Atomic Safety and Licensing Board Panel....

2010-08-30

314

Criteria for the safe storage of enriched uranium at the Y-12 Plant  

SciTech Connect

Uranium storage practices at US Department of Energy (DOE) facilities have evolved over a period spanning five decades of programmatic work in support of the nuclear deterrent mission. During this period, the Y-12 Plant in Oak Ridge, Tennessee has served as the principal enriched uranium facility for fabrication, chemical processing, metallurgical processing and storage. Recent curtailment of new nuclear weapons production and stockpile reduction has created significant amounts of enriched uranium available as a strategic resource which must be properly and safely stored. This standard specifies criteria associated with the safe storage of enriched uranium at the Y-12 Plant. Because programmatic needs, compliance regulations and desirable materials of construction change with time, it is recommended that these standards be reviewed and amended periodically to ensure that they continue to serve their intended purpose.

Cox, S.O.

1995-07-01

315

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

316

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.

Grossman, Mark W. (Belmont, MA)

1991-01-01

317

Mutant Enrichment with 3?-Modified Oligonucleotides  

PubMed Central

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

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

2011-01-01

318

Chemoselective probes for metabolite enrichment and profiling.  

PubMed

Chemical probes that target classes of proteins based on shared functional properties have emerged as powerful tools for proteomics. The metabolome rivals, if not surpasses, the proteome in terms of size and complexity, suggesting that efforts to profile metabolites would also benefit from targeted technologies. Here we apply the principle of chemoselective probes to the metabolome, creating a general strategy to tag, enrich and profile large classes of small molecules from biological systems. Key to success was incorporation of a protease-cleavage step to release captured metabolites in a format compatible with liquid chromatography-mass spectrometry (LC-MS) analysis. This technology, termed metabolite enrichment by tagging and proteolytic release (METPR), is applicable to small molecules of any physicochemical class, including polar, labile and low-mass (<100 Da) compounds. We applied METPR to profile changes in the thiol metabolome of human cancer cells treated with the antioxidant N-acetyl-L-cysteine. PMID:17417646

Carlson, Erin E; Cravatt, Benjamin F

2007-04-08

319

Nuclear criticality safety of low-enriched uranium systems  

SciTech Connect

Large quantities of low-enriched uranium (LEU) 0.71 to 1.25 wt% {sup 235}U were processed into metallic fuel elements and irradiated in production reactors at the Hanford and the Savannah River sites. Safe processing was ensured by strict adherence to nuclear criticality controls. A criticality control approach emerged for N Reactor fuels that established a k{sub eff} = 0.98 as the safety limit rather than a k{sub eff} = 0.95 used by the commerical power industry for their fuels. This paper demonstrates that the use of k{sub eff} = 0.98 provides equivalent or larger safety margins for N Reactor fuels than k{sub eff} = 0.95 provides for commercial reactor fuels. Recent accident analyses pertaining to N Reactor spent-fuel storage are used to illustrate compliance with the k{sub eff} = 0.98 limit.

Toffer, H.; Wittekind, W.D.; Schwinkendorf, K.N. (Westinghouse Hanford Co., Richland, WA (United States))

1992-01-01

320

21 CFR 139.135 - Enriched vegetable macaroni products.  

Code of Federal Regulations, 2013 CFR

...enriched macaroni product containing the prescribed amount of spinach and made in units not conforming in shape and size to the requirements for macaroni, spaghetti, or vermicelli is âEnriched spinach macaroni productâ. [42 FR 14409, Mar. 15, 1977,...

2013-04-01

321

21 CFR 139.165 - Enriched vegetable noodle products.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Enriched vegetable noodle products. 139.165 Section 139...FOOD FOR HUMAN CONSUMPTION MACARONI AND NOODLE PRODUCTS Requirements for Specific Standardized Macaroni and Noodle Products § 139.165 Enriched...

2010-04-01

322

21 CFR 139.165 - Enriched vegetable noodle products.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Enriched vegetable noodle products. 139.165 Section 139...FOOD FOR HUMAN CONSUMPTION MACARONI AND NOODLE PRODUCTS Requirements for Specific Standardized Macaroni and Noodle Products § 139.165 Enriched...

2009-04-01

323

BAM Media M109: Nitrate Broth, Enriched (CDC)  

Center for Food Safety and Applied Nutrition (CFSAN)

... BAM Media M109: Nitrate Broth, Enriched (CDC). January 2001. Bacteriological Analytical Manual. M109 Nitrate Broth, Enriched (CDC). ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

324

21 CFR 139.155 - Enriched noodle products.  

Code of Federal Regulations, 2013 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of any...

2013-04-01

325

21 CFR 139.115 - Enriched macaroni products.  

Code of Federal Regulations, 2013 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of...

2013-04-01

326

LL Bakery, Inc. Announces the Recall of White Farm Enriched ...  

Center for Food Safety and Applied Nutrition (CFSAN)

of Torrance, CA is recalling all White Farm Enriched White Bread, Butter Farm Enriched White Bread, and Italian Cream Danish because product ... More results from www.fda.gov/food/recallsoutbreaksemergencies/recalls

327

Microbial response to a mesoscale iron enrichment in the NE Subarctic Pacific: Bacterial community composition  

NASA Astrophysics Data System (ADS)

Changes in microbial community composition were determined during the subarctic ecosystem response to iron enrichment study (SERIES), a mesoscale Fe enrichment conducted in a high-nutrient low-chlorophyll (HNLC) region of the Northeast Subarctic Pacific, in July 2002. Phylogenetic composition using fluorescence in situ hybridization (FISH), relative DNA content using flow cytometry (FCM), and cellular morphometrics (shape and volume) of heterotrophic bacteria were used to characterize community composition from samples collected within and below the mixed layer, inside and outside the Fe-patch. The proportion of total cells detected as members of the Cytophaga-Flavobacterium cluster increased in a log-linear manner from 16 (±1.0)% to 47 (±1.9)% in samples within the mixed layer, inside the Fe-enriched patch, while outside the patch, the proportion remained ?21 (±2.2)%. Temporal changes in the proportion of cells in the mixed layer with high DNA content (% HDNA) were significantly different inside and outside the Fe-enriched patch, where inside the patch % HDNA increased 2-fold after a week, reaching 93% towards the end of the observation period. Coupling in situ observations with the results of manipulation experiments allowed us to determine the relative contributions of bottom-up (nutrient limitation) and top-down (grazing) processes on heterotrophic bacterial abundance and community composition. Shifts in heterotrophic bacterial community composition inside the Fe-enriched patch were mainly controlled by top-down processes and moderately controlled by bottom-up controls (organic substrate limitation).

Agawin, Nona S. R.; Hale, Michelle S.; Rivkin, Richard B.; Matthews, Paul; Li, William K. W.

2006-10-01

328

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

329

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.

Palumbo, Samuel A.; Alford, John A.

1970-01-01

330

Enriching Rotifers with “Premium” Microalgae. Nannochloropsis gaditana  

Microsoft Academic Search

The nutritive quality of Nannochloropsis gaditana cultured semicontinuously with different daily renewal rates was tested as a diet for short-term enrichment of the rotifer\\u000a Brachionus plicatilis. After 24 h, dramatic differences in the survival, dry weight, and biochemical composition of the rotifers depending on the\\u000a renewal rate of microalgal cultures were observed. Survival after the feeding period increased with increasing renewal

Martiña Ferreira; Paula Coutinho; Pedro Seixas; Jaime Fábregas; Ana Otero

2009-01-01

331

Update on international uranium and enrichment supply  

SciTech Connect

Commercial nuclear power generation came upon us in the late 1950s and should have been relatively uneventful due to its similarities to fossil-powered electrical generation. Procurement of nuclear fuel appears to have been treated totally different from the procurement of fossil fuel, however, and only recently have these practices started to change. The degree of utility reliance on US-mined uranium and US Dept. of Energy (DOE)-produced enrichment services has changed since the 1970s as federal government uncertainty, international fuel market opportunity, and public service commission scrutiny has increased. Accordingly, the uranium and enrichment market has recognized that it is international just like the fossil fuel market. There is now oversupply-driven competition in the international nuclear fuel market. Competition is increasing daily, as third-world countries develop their own nuclear resources. American utilities are now diversifying their fuel supply arrangements, as they do with their oil, coal, and gas supply. The degree of foreign fuel arrangements depends on each utility's risk posture and commitment to long-term contracts. In an era of rising capital, retrofit, operating, and maintenance costs, economical nuclear fuel supply is even more important. This economic advantage, however, may be nullified by congressional and judicial actions limiting uranium importation and access to foreign enrichment. Such artificial trade barriers will only defeat US nuclear generation and the US nuclear fuel industry in the long term.

Cleveland, J.M.

1987-01-01

332

DOE's allocation of costs for uranium enrichment services  

SciTech Connect

In order to more fairly price uranium enrichment services, GAO recommended that DOE account separately for the costs of providing high and low enrichment services and using such cost information, establish separate enrichment prices for each customer. Audits occured in Maryland, Tennessee and Kentucky.

Not Available

1983-11-15

333

In situ nitrogen enriched carbon for carbon dioxide capture  

Microsoft Academic Search

In situ nitrogen enriched carbon was synthesized from locally available low cost soybean as the proteinaceous source. The material was synthesized by chemical activation using zinc chloride followed by physical activation using CO2. The surface area of synthesized nitrogen enriched carbon was found to be 811m2\\/g which is comparable with commercially available activated carbon. The nitrogen enriched carbon was having

Jayshri A. Thote; Kartik S. Iyer; Ravikrishna Chatti; Nitin K. Labhsetwar; Rajesh B. Biniwale; Sadhana S. Rayalu

2010-01-01

334

Targeted enrichment of genomic DNA regions for next generation sequencing  

Microsoft Academic Search

In this review we discuss the latest targeted enrichment methods, and aspects of their utilization along with second generation sequencing for complex genome analysis. In doing so we provide an overview of issues involved in detecting genetic variation, for which targeted enrichment has become a powerful tool. We explain how targeted enrichment for next generation sequencing has made great progress

F. Mertens; A. El-Sharawy; S. Sauer; J. Van Helvoort; P. J. Van der Zaag; A. Franke; M. Nilsson; Lehrach. H; A. Brookes

2011-01-01

335

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.

336

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

337

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; Uckan, Taner [ORNL

2010-01-01

338

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

339

Phosphate recovery as concentrated solution from treated wastewater by a PAO-enriched biofilm reactor.  

PubMed

Phosphorus recovery from wastewaters and its recycling are of importance for sustaining agricultural production. During the conventional enhanced biological phosphorus removal process, phosphorus is removed by withdrawing excess sludge from wastewater. However, excess sludge disposal is costly and energy intensive. A proposed novel process for phosphorus recovery from sewage treatment will result in no excess sludge if a polyphosphate accumulating organisms (PAOs) enrichment biofilm can be applied to effluents containing phosphate. This process allows the recovery of phosphate as phosphate-concentrated solutions by controlling PAOs to absorb and release phosphate. A reactor consisting of a modified trickling filter with a synthetic substrate (5 mg P L?¹) was operated to form a PAO-enriched biofilm. As a result of the enrichment, the concentration of phosphate of >100 mg P L?¹ was successfully achieved. During this experiment, no sludge withdrawal was carried out over the duration of the operation of 255 days. To highlight the new process, the principle of enriching PAOs on biofilm and concentrating phosphate from treated sewage is explained, and a discussion on phosphate recovery performance is given. PMID:23415245

Kodera, Hiroya; Hatamoto, Masashi; Abe, Kenichi; Kindaichi, Tomonori; Ozaki, Noriatsu; Ohashi, Akiyoshi

2013-01-31

340

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

341

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

Microsoft Academic Search

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

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

2006-01-01

342

Enrichment of polyunsaturated fatty acids from tuna oil using immobilized Pseudomonas fluorescens lipase  

Microsoft Academic Search

Immobilized Pseudomonas fluorescens lipase enzyme was used to enrich the important polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from tuna oil. Hydrolysis, esterification, and transesterification reactions were studied in detail to find out the fractionation pattern of DHA and EPA during these processes due to preferential selectivity for or against these PUFA. Hydrolysis with P. fluorescens

S. K. Rakshit; R. Vasuhi; Y. Kosugi

2000-01-01

343

Enriched collagen solution as a pulp dressing in pulpotomized teeth in monkeys  

Microsoft Academic Search

The purpose of this study was to assess the pulp healing process in baboon teeth after pulpotomy using an enriched collagen solution (ECS) as a pulp dressing. Twenty-five noncarious permanent teeth of two young baboon monkeys were pulpotomized under a rubber dam. After coronal pulp resection and hemostasis, ECS was applied on the pulp stumps and covered with sterile dental

Anna B. Fuks; S. Shoshan; Y. Michaeli

1984-01-01

344

[Fortification and enrichment of foods: considerations on their use for achieving nutritional goals].  

PubMed

The diet should, ideally, provide adequate amounts of all nutrients. The traditional foods of many Latin American countries, however, must be fortified or enriched with certain nutrients to satisfy the needs of the whole population. These measures should be considered as temporary, until improvements are achieved in dietary diversification, economic conditions, nutrition education and food processing and storage. Restoration of nutrients lost during cooking or processing and equalization of new foods with the nutrients present in traditional foods, are also important. Conditions for a successful program of fortification or enrichment include a widespread and regular intake of the dietary vehicle, high bioavailability of the added nutrient, low costs of the nutrient and the fortified vehicle, central processing, organoleptic characteristics that ensure acceptability, stability of the product during storage and cooking, no risk of toxicity, and adequate control during the process, distribution, marketing and consumption of the fortified vehicle or food. Control measures must be supported by legal sanctions to those who do not comply with the norms for obligatory fortification or enrichment. Control measures must also identify the necessary modifications due to changes in dietary habits or public health interventions. In Latin America there are fortification and enrichment programs with various nutrients in which local diets are scarce. Many Latin American scientists have been pioneers in this field. PMID:3153131

Torún, B

1988-09-01

345

Advanced DHA, EPA and ArA enrichment materials for marine aquaculture using single cell heterotrophs  

Microsoft Academic Search

Heterotrophically grown algae and fungal biomass and their residual materials from an industrial oil extraction process were used as components in marine larval and broodstock diets. Crypthecodinium sp. phospholipid extract and meal, used to enrich rotifers and Artemia nauplii, produced higher levels of DHA and higher DHA\\/EPA ratios in these zooplankters than Schizochytrium sp. algal whole cell preparation or fish

Moti Harel; William Koven; Ingrid Lein; Yoav Bar; Paul Behrens; John Stubblefield; Yoni Zohar

2002-01-01

346

Enrichment and Purification of Total Chlorogenic Acids from Tobacco Waste Extract with Macroporous Resins  

Microsoft Academic Search

In the present study, an evaluation was conducted on the performance and separation characteristics of nine macroporous resins for the enrichment and purification of total chlorogenic acids from tobacco (Nicotiana tobaccum L.) waste extracts. Based on the results, XAD-4 offered higher adsorption and desorption capacities for total chlorogenic acids than other resins. To optimize the separation process of total chlorogenic

Zhao Hui; Wang Jun; Jia Jing; Liu Ji; Ling Xiuquan; Lu Dingqiang

2010-01-01

347

ENCORE: The Effect of Nutrient Enrichment on Coral Reefs. Synthesis of Results and Conclusions  

Microsoft Academic Search

Coral reef degradation resulting from nutrient enrichment of coastal waters is of increasing global concern. Although effects of nutrients on coral reef organisms have been demonstrated in the laboratory, there is little direct evidence of nutrient effects on coral reef biota in situ. The ENCORE experiment investigated responses of coral reef organisms and processes to controlled additions of dissolved inorganic

K. Koop; D. Booth; Andrew D Broadbent; J. Brodie; Daniel J Bucher; D. Capone; J. Coll; W. Dennison; M. Erdmann; Peter Lynton Harrison; O. Hoegh-Guldberg; P. Hutchings; Graham B Jones; A. W. D. Larkum; J. O'Neil; A. Steven; E. Tentori; S. Ward; J. Williamson; D. Yellowlees

2001-01-01

348

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

349

Chiral enrichment of serine via formation, dissociation, and soft-landing of octameric cluster ions  

Microsoft Academic Search

Chiral enrichment of serine is achieved in experiments that involve formation of serine octamers starting from non-racemic\\u000a serine solutions. Serine octamers were generated by means of electrospray and sonic spray ionization of aqueous solutions\\u000a of d\\u000a 3-L-serine (108 Da) and D-serine (105 Da) having different molar ratios of enantiomers. A cyclic process involving the formation\\u000a of chirally-enriched octameric cluster ions

Sergio C. Nanita; Zoltan Takats; R. Graham Cooks; Sunnie Myung; David E. Clemmer

2004-01-01

350

PREPARING THE HIGH FLUX ISOTOPE REACTOR FOR CONVERSION TO LOW ENRICHED URANIUM FUEL ? EXTENDING CYCLE BURNUP  

SciTech Connect

Reactor performance studies have been completed for conceptual plate designs and show that maintaining reactor performance while converting HFIR from high enriched to low enriched uranium (20 wt % 235U) fuel requires extending the end-of-life burnup value for HFIR fuel from the current nominal value of 2200 MWD to 2600 MWD. The current fuel fabrication procedure is discussed and changes that would be required to this procedure are identified. Design and safety related analyses that are required for the certification of a new fuel are identified. Qualification tests and comments regarding the regulatory approval process are provided along with a conceptual schedule.

Primm, Trent [ORNL; Chandler, David [ORNL

2009-01-01

351

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

PubMed

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

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

2012-07-01

352

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

353

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.

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

1985-01-01

354

NDA measurement of the enrichment of uranium in the pipe for a gas centrifuge enrichment plant  

SciTech Connect

A NDA instrument has been developed to determine the enrichment of gas phase uranium in pipes for a gas centrifuge enrichment plant. The enrichment of gas phase uranium could be measured by combining the passive gamma rays measurement with X-ray fluorescent analysis. The passive gamma rays measurement has extensively been performed in previous works. Successively the amount of deposited uranium has been measured for a long-term plant operation. Some increase of deposited uranium was observed. Determination of total mass of uranium in a pipe was studied by X-ray fluorescent analysis on a test loop system. It was found that total mass of gaseous UF/sub 6/ in the pipe could be determined accurately enough in implementation of safeguards.

Hori, M.; Ishiga, T.; Akiba, M.; Tani, A.; Omae, M.

1986-01-01

355

Improved Enrichment and Isolation of Polycyclic Aromatic Hydrocarbons (PAH)Degrading Microorganisms in Soil Using Anthracene as a Model PAH  

Microsoft Academic Search

Lack of attention to soil and microbial characteristics that influence PAHs degradation has been a leading cause of failures\\u000a in isolation of efficient PAH degraders and bioaugumentation processes with microbial consortia. This study compared the classic\\u000a method of isolation of PAHs-degraders with a modified method employing a pre-enrichment respirometric analysis. The modified\\u000a enrichment of PAH degrading microorganisms using in vitro

Rodrigo J. S. Jacques; Benedict C. Okeke; Fátima M. Bento; Maria C. R. Peralba; Flávio A. O. Camargo

2009-01-01

356

The Fluorescence Characteristics of Enrichment Media in the Wavelength Range of Real-Time PCR Thermocycler Optical Path Assignments  

Microsoft Academic Search

The aim of this study was to investigate the fluorescence characteristics of common enrichment media with regard to disturbance\\u000a of fluorescence readings of real-time polymerase chain reaction (PCR) reactions. Confirmation of effective amplification of\\u000a target DNA during the real-time PCR process depends on measurement of the fluorescence emitted from the probe fluorophore\\u000a used. Possible background fluorescence emitted from enrichment media,

Peter Rossmanith; Sabine Fuchs; Martin Wagner

2010-01-01

357

Carbon13 solid-state n.m.r. study of 1 3C-enriched human hair keratin  

Microsoft Academic Search

The 13C-enriched human hair was prepared by labeling human hair with 13C-enriched methyl iodide for the thiol groups formed by reduction of the disulfide bonds. In the 13C CP\\/MAS n.m.r. spectrum, the Cys S-13CH3 peak split into two peaks with a chemical shift difference of 1.7ppm. With increasing reduction time in the process of the sample preparation, the relative intensity

Noaki Nishikawa; Yasunobu Horiguchi; Tetsuo Asakura; Isao Ando

1999-01-01

358

Enhancement of cognitive function in models of brain disease through environmental enrichment and physical activity.  

PubMed

This review will provide an overview of the non-drug based approaches that have been demonstrated to enhance cognitive function of the compromised brain, primarily focussed on the two most widely adopted paradigms of environmental enrichment and enhanced physical exercise. Environmental enrichment involves the generation of novelty and complexity in animal housing conditions which facilitates enhanced sensory and cognitive stimulation as well as physical activity. In a wide variety of animal models of brain disorders, environmental enrichment and exercise have been found to have beneficial effects, including cognitive enhancement, delayed disease onset, enhanced cellular plasticity and associated molecular processes. Potential cellular and molecular mechanisms will also be discussed, which have relevance for the future development of 'enviromimetics', drugs which could mimic or enhance the beneficial effects of environmental stimulation. This article is part of a Special Issue entitled 'Cognitive Enhancers'. PMID:22766390

Pang, Terence Y C; Hannan, Anthony J

2012-07-02

359

Unconventional approaches to isolation and enrichment of functional microbial consortium--a review.  

PubMed

Studies on how different functional strains interact in a microflora may include isolation of pure strains using conventional plating technique and then mix a few of the isolates before observing their growth in specific medium. As isolating pure strains that take part in the key function of industrial effluent purification via conventional method is impractical, convenient alternative approaches to screen essential microbial group that maintains desired function of a mixed population is desired. Such approaches can be employed to allow the selection and enrichment of so-called functional consortium with user-defined attributes for specific functions. This manuscript provides a review of various approaches to isolation and enrichment of microbial functional consortium in several biological processes. Consideration for the isolation and enrichment approaches and their applications are delineated. Challenges to the applications and further work are also outlined. PMID:23566469

Lee, Duu-Jong; Show, Kuan-Yeow; Wang, Aijie

2013-03-01

360

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

361

DEFOG: Discrete Enrichment of Functionally Organized Genes†  

PubMed Central

High-throughput biological experiments commonly result in a list of genes or proteins of interest. In order to understand the observed changes of the genes and to generate new hypotheses, one needs to understand the functions and roles of the genes and how those functions relate to the experimental conditions. Typically, statistical tests are performed in order to detect enriched Gene Ontology categories or Pathways, i.e. the categories are observed in the genes of interest more often than is expected by chance. Depending on the number of genes and the complexity and quantity of functions in which they are involved, such an analysis can easily result in hundreds of enriched terms. To this end we developed DEFOG, a web-based application that facilitates the functional analysis of gene sets by hierarchically organizing the genes into functionally related modules. Our computational pipeline utilizes three powerful tools to achieve this goal: (1) GeneMANIA creates a functional consensus network of the genes of interest based on gene-list-specific data fusion of hundreds of genomic networks from publicly available sources; (2) Transitivity Clustering organizes those genes into a clear hierarchy of functionally related groups, and (3) Ontologizer performs a Gene Ontology enrichment analysis on the resulting gene clusters. DEFOG integrates this computational pipeline within an easy-to-use web interface, thus allowing for a novel visual analysis of gene sets that aids in the discovery of potentially important biological mechanisms and facilitates the creation of new hypotheses. DEFOG is available at http://www.mooneygroup.org/defog.

Wittkop, Tobias; Berman, Ari E.; Fleisch, K. Mathew; Mooney, Sean D.

2012-01-01

362

Effect of gas enrichment and numerical dispersion on enriched-gas-drive predictions  

SciTech Connect

This paper examines the effect of gas enrichment in reservoir-scale enriched-gas-drive displacements through predictions made with a compositional simulator and the Peng-Robinson equation of state (PREOS). The calculations examine behavior for a classical three-component condensing-gas drive and for a 12-component reservoir-fluid characterization that predicts condensing/vaporizing-gas-drive behavior. The predictions also illustrate behavior for two simplified reservoir analogues: a homogeneous cross section with a low vertical/horizontal permeability ratio and a stratified cross section.

Stalkup, F.I. (Arco Oil and Gas Co., Plano, TX (US))

1990-11-01

363

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

364

Surplus Highly Enriched Uranium Disposition Program plan  

SciTech Connect

The purpose of this document is to provide upper level guidance for the program that will downblend surplus highly enriched uranium for use as commercial nuclear reactor fuel or low-level radioactive waste. The intent of this document is to outline the overall mission and program objectives. The document is also intended to provide a general basis for integration of disposition efforts among all applicable sites. This plan provides background information, establishes the scope of disposition activities, provides an approach to the mission and objectives, identifies programmatic assumptions, defines major roles, provides summary level schedules and milestones, and addresses budget requirements.

NONE

1996-10-01

365

Active interrogation of highly enriched uranium  

NASA Astrophysics Data System (ADS)

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

Fairrow, Nannette Lea

366

Method and apparatus for fuel mixture enrichment during acceleration  

SciTech Connect

The fuel mixture preparation system of an internal combustion engine, especially a continuous fuel injection system, is engaged during intended engine accelerations by a pressure sensor in the induction manifold which responds to increasing manifold pressure to close a switch. The switch closure affects a pressure control valve that changes the control pressure in the fuel injection system and thereby causes temporary fuel enrichment until the differential pressure in the pressure sensor has returned to equilibrium. The signal from the pressure sensor may be extended arbitrarily by interposition of an electronic timing circuit which is constructed as an integrating circuit so that its output signal, when processed by a comparator, will produce a proportionally extended actuation signal for the control valve.

Glockler, O.; Herth, H.; Kraus, B.; Wilfert, T.

1980-09-23

367

Gender-Dependent Effects of Enriched Environment and Social Isolation in Ischemic Retinal Lesion in Adult Rats  

PubMed Central

Exposure to an enriched environment has been shown to have many positive effects on brain structure and function. Numerous studies have proven that enriched environment can reduce the lesion induced by toxic and traumatic injuries. Impoverished environment, on the other hand, can have deleterious effects on the outcome of neuronal injuries. We have previously shown that enriched conditions have protective effects in retinal injury in newborn rats. It is well-known that the efficacy of neuroprotective strategies can depend on age and gender. The aim of the present study, therefore, was to examine the effects of environmental enrichment and social isolation in retinal ischemia. We used bilateral common carotid artery occlusion to induce retinal hypoperfusion in adult Wistar rats of both genders. Groups were housed in standard, enriched or impoverished conditions. Impoverished environment was induced by social isolation. Retinas were processed for histological analysis after two weeks of survival. In the present study, we show that (1) enriched environment has protective effects in adult ischemic retinal lesion, while (2) impoverished environment further increases the degree of ischemic injury, and (3) that these environmental effects are gender-dependent: females are less responsive to the positive effects of environmental enrichment and more vulnerable to retinal ischemia in social isolation. In summary, our present study shows that the effects of both positive and negative environmental stimuli are gender-dependent in ischemic retinal lesions.

Kiss, Peter; Szabadfi, Krisztina; Horvath, Gabor; Tamas, Andrea; Farkas, Jozsef; Gabriel, Robert; Reglodi, Dora

2013-01-01

368

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.

369

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

Microsoft Academic Search

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

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

2011-01-01

370

Accurate, wide-range uranium enrichment measurements by gamma-ray spectroscopy: 1, Characterization of enrichment standards; 2, Demonstration of enrichment measurement capability  

SciTech Connect

Section 1 describes the repackaging and recharacterization of 19 approximately 1-kg lots of uranium oxides, with enrichments (/sup 235/U at. %) ranging from 0.7 to 91 at. %, for use primarily as working standards in gamma-ray enrichment measurements. The results of all characterization analyses are given. Section 2 describes demonstration gamma-ray enrichment measurements on the Los Alamos National Laboratory standards and on the National Bureau of Standards (NBS) certified enrichment reference standards (NBS SRM-969). We consider in some detail both the theoretical and experimental considerations of doing accurate gamma-ray measurement of uranium enrichment, including particularly the extraction of the net area of spectral full-energy peaks, correction for deadtime and pileup losses, correction for the chemical composition of the measured materials, and correction for the attenuation in containers. We conclude that with proper procedures and careful work, gamma-ray enrichment measurements based on a minimum set of standards (perhaps only one of high enrichment) can be made over the whole range of enrichments greater than or equal to0.7% with biases of less than or equal to0.1%. 6 refs., 34 figs., 8 tabs.

Parker, J.L.; Brooks, M.

1988-09-01

371

An Enriched Teaching Program For Reducing Resistance And Indices Of Unhappiness Among Individuals With Profound Multiple Disabilities  

PubMed Central

We evaluated an enriched teaching program for reducing resistance and indices of unhappiness displayed by 3 individuals with profound multiple disabilities during teaching sessions. The program involved presentation of preferred activities before, during, and after each teaching session, discontinuation of identified nonpreferred activities, and a brief break and preferred activity following occurrence of resistance. Implementation of the enriched teaching program was accompanied by reductions in resistance and indices of unhappiness for each participant. Results also indicated no negative impact of the program on participant performance of the teaching steps or staff teaching proficiency. Staff questionnaire responses provided a degree of social validation for the observed changes in that staff reported the participants liked the enriched teaching program more than the traditional teaching process. Directions for future research discussed include identifying critical aspects of the overall program and the potential relation between teaching proficiency and the program's enrichment effectiveness.

2005-01-01

372

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

373

Assuaging Nuclear Energy Risks: The Angarsk International Uranium Enrichment Center  

SciTech Connect

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 [Stanford University, Stanford, CA 94305, USA and MonAme Scientific Research Center, Ulaanbaatar (Mongolia)

2011-06-28

374

Fiber enriched diets and radiation induced injury of the gut  

Microsoft Academic Search

The aim of this study was to evaluate the effect of fiber-enriched defined formula diets (DFDs) on radiation-induced enteropathy. Forty-five male Sprague-Dawley rats were assigned randomly after abdominal irradiation to one of three groups (15 in each group): a fiber-free DFD group, a non-soluble fiber-enriched DFD group, and a soluble fiber-enriched DFD group. They kept their diets respectively for seven

Murat Kapkac; Mehmet Erikoglu; Pars Tuncyurek; Sinan Ersin; Mustafa Esassolak; Murat Alkanat; Oguz Sipahioglu

2003-01-01

375

Effect of phase behavior on bypassing in enriched gas floods  

SciTech Connect

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

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

1994-05-01

376

Functional properties of pasta enriched with variable cereal brans  

Microsoft Academic Search

To explore the potentiality of cereal brans for preparation of fiber enriched pasta, various cereal brans (Wheat, Rice, Barley\\u000a and Oat) were added at 0, 5, 10, 15, 20 and 25 per cent to durum wheat semolina. The effect of cereal bran enrichment on the\\u000a colour, cooking, sensory quality and shelf life of enriched pasta was assessed at ambient temperature.

Gurkirat Kaur; Savita Sharma; H. P. S. Nagi; Basharat N. Dar

377

Enrichment of surfactant from its aqueous solution using ultrasonic atomization  

Microsoft Academic Search

Dilute aqueous solutions of dodecyl-benzenesulfonic acid sodium salt (DBS-Na) and polyoxyethylenenonylphenyl ethers (PONPEs) were ultrasonically atomized. The surfactants were concentrated in collected mist droplets. The enrichment ratio increased with decreasing surfactant concentration. Depending on the surfactant’s molecular weight and affinity to water, different enrichment ratio was observed in the range of low feed concentrations. For anionic surfactant, DBS-Na, the enrichment

Haruko Takaya; Susumu Nii; Fumio Kawaizumi; Katsuroku Takahashi

2005-01-01

378

Biodegradation of PAH Mixtures by a Marine Sediment Enrichment  

Microsoft Academic Search

Aerobic polycyclic aromatic hydrocarbon (PAH) degrading bacteria were enriched from creosote contaminated marine sediments (Puget Sound, Washington, USA) using a continuous-flow fluidized-bed reactor. Artificial seawater media and a mixture of seven 2 to 3-ring PAHs were used as enrichment substrates. The biodegradability of PAH mixtures by the enrichment was determined in batch vial assays. The tested PAH mixtures included alkyl

Minna K. Männistö; Esa S. Melin; Jaakko A. Puhakka; John F. Ferguson

1996-01-01

379

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.

Nelson, Craig E.; Carlson, Craig A.

2011-01-01

380

A Method for Selective Enrichment and Analysis of Nitrotyrosine-Containing Peptides in Complex Proteome Samples  

SciTech Connect

Elevated levels of protein tyrosine nitration have been found in various neurodegenerative diseases and aging related pathologies; however, the lack of an efficient enrichment method has prevented the analysis of this important low level protein modification. We have developed an efficient method for specific enrichment of nitrotyrosine containing peptides that permits nitrotyrosine peptides and specific nitration sites to be unambiguously identified with LC-MS/MS. The method is based on the derivatization of nitrotyrosine into free sulfhydryl groups followed by high efficiency enrichment of sulfhydryl-containing peptides with thiopropyl sepharose beads. The derivatization process starts with acetylation with acetic anhydride to block all primary amines, followed by reduction of nitrotyrosine to aminotyrosine, then derivatization of aminotyrosine with N-Succinimidyl S-Acetylthioacetate (SATA), and finally deprotecting of S-acetyl on SATA to form free sulfhydryl groups. This method was evaluated using nitrotyrosine containing peptides, in-vitro nitrated human histone 1.2, and bovine serum albumin (BSA). 91% and 62% of the identified peptides from enriched histone and BSA samples were nitrotyrosine derivatized peptides, respectively, suggesting relative high specificity of the enrichment method. The application of this method to in-vitro nitrated mouse brain homogenate resulted in 35% of identified peptides containing nitrotyrosine (compared to only 5.9% observed from the global analysis of unenriched sample), and a total of 150 unique nitrated peptides covering 102 proteins were identified with a false discovery rate estimated at 3.3% from duplicate LC-MS/MS analyses of a single enriched sample.

Zhang, Qibin; Qian, Weijun; Knyushko, Tanya V.; Clauss, Therese RW; Purvine, Samuel O.; Moore, Ronald J.; Sacksteder, Colette A.; Chin, Mark H.; Smith, Desmond J.; Camp, David G.; Bigelow, Diana J.; Smith, Richard D.

2007-06-01

381

Mineralization of Trichloroethylene by Heterotrophic Enrichment Cultures  

PubMed Central

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

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

1988-01-01

382

[Enriched-enrollment randomized-withdrawal trials].  

PubMed

A clinical trial's power depends on the probability of observing an effect of the tested drug in the trial population, on the size of this effect, and on the heterogeneousness of the judgment criterion in the population. Enriched-enrollment randomized-withdrawal trials are clinical trials which comprise a first period in which subjects are selected depending on whether they respond to the tested drug or not. The responding patients are subsequently randomized into 2 groups: in one of them the treatment is pursued, in the other group a placebo is substituted. These designs are very useful in pediatrics, decreasing the number of subjects needed, on condition that the effect of the treatment is only suspensive in a setting of chronic disease. Here we discuss the advantages and disadvantages of such trials. PMID:22236550

Merlin, E; Pereira, B; Nourrissat, A

2012-01-10

383

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

384

Process for coal liquefaction  

SciTech Connect

In two stage solvent refining of coal by mixing comminuted coal with a solvent produced in the process under hydrogen pressure for initial solubilization and reacting the mixture under hydrogen pressure in a second stage, the overall process is improved by enriching the recycled solvent in hydroaromatic hydrocarbons of fourteen or less carbon atoms.

Farcasiu, M.; Mitchell, T.O.; Whitehurst, D.D.

1983-02-22

385

Foreign enrichment of uranium for US nuclear utilities  

SciTech Connect

The entrance of foreign suppliers of enrichment services into an already oversupplied market at prices below the DOE's price for separative work units (SWUs) could have a long-term effect on domestic enrichment programs. State regulators are urging utilities to cut costs (in this case by purchasing foreign SWUs) in contrast to resistance to foreign dumping of surpluses. At issue is whether domestic enrichment, which provides about 30% of DOE sales, is to remain economically viable. The author examines the economic and contractual implications of foreign enrichment. (DCK)

Einbund, D.R.

1983-04-14

386

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

387

Odor enrichment sculpts the abundance of olfactory bulb mitral cells.  

PubMed

Mitral cells are the primary output cell from the olfactory bulb conveying olfactory sensory information to higher cortical areas. Gene-targeted deletion of the Shaker potassium channel Kv1.3 alters voltage-dependence and inactivation kinetics of mitral cell current properties, which contribute to the "Super-smeller" phenotype observed in Kv1.3-null mice. The goal of the current study was to determine if morphology and density are influenced by mitral cell excitability, olfactory environment, and stage of development. Wildtype (WT) and Kv1.3-null (KO) mice were exposed to a single odorant (peppermint or citralva) for 30 days. Under unstimulated conditions, postnatal day 20 KO mice had more mitral cells than their WT counterparts, but no difference in cell size. Odor-enrichment with peppermint, an olfactory and trigeminal stimulus, decreased the number of mitral cells in three month and one year old mice of both genotypes. Mitral cell density was most sensitive to odor-stimulation in three month WT mice. Enrichment at the same age with citralva, a purely olfactory stimulus, decreased cell density regardless of genotype. There were no significant changes in cell body shape in response to citralva exposure, but the cell area was greater in WT mice and selectively greater in the ventral region of the OB in KO mice. This suggests that trigeminal or olfactory stimulation may modify mitral cell area and density while not impacting cell body shape. Mitral cell density can therefore be modulated by the voltage and sensory environment to alter information processing or olfactory perception. PMID:23485739

Johnson, Melissa Cavallin; Biju, K C; Hoffman, Joshua; Fadool, Debra Ann

2013-02-26

388

Nuclear Material Safeguards for Enrichment Plants: Part 3, Gas Centrifuge Enrichment Plant: Description, Material Control and Accountability Procedures, and IAEA Safeguards: Safeguards Training Course.  

National Technical Information Service (NTIS)

This 5-day training course on nuclear material safeguards for uranium enrichment plants has been developed to train IAEA professionals who are responsible for safeguarding uranium enrichment facilities on the safeguards relevant principles of enrichment t...

1987-01-01

389

Enrichment-induced exercise to quantify the effect of different housing conditions: a tool to standardize enriched environment protocols.  

PubMed

Enriched environments (EE) have been used for a long time to promote recovery in many neurological disorders, however, a growing body of inconsistent results strongly calls for a rigorous standardization of experimental EE paradigms. Although some core principles are well accepted as standards, a method to quantitatively assess the complexity of EE in various experimental designs is still lacking. In this study, we tracked and recorded the physical exercise of rats in four housing conditions, namely isolated condition, social condition, novel condition and EE. Then, we analyzed whether and to what extent, enrichment-induced exercise reflected the degree of enrichment. We next examined rat exercise in a conventional environment condition and under different light intensities, to explore whether environment-related exercise could be considered a parameter to quantify the degree of enrichment. The results obtained showed that (1) both inanimate and social stimulations enhanced the exercise level and (2) EE combined the effects of the two stimulations. Furthermore, exercise durability which correlated positively with degree of enrichment, was an objective measure of different housing conditions. Exercise-related parameters also sensitively reflected the impacts of light intensity even in the same enrichment arrangements. Our results indicate that there is a direct and measurable correlation between degree of environmental enrichment and enrichment-induced exercise, and therefore enrichment-induced exercise could be used as a helpful tool to evaluate the degree of housing conditions and to standardize the EE protocols. PMID:23624191

Xie, Hongyu; Wu, Yi; Jia, Jie; Liu, Gang; Zhang, Qi; Yu, Kewei; Guo, Zhenzhen; Shen, Li; Hu, Ruiping

2013-04-26

390

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

PubMed

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

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

2009-12-01

391

Arsenic Enrichment in Surface Water and Soil in Tibetan Plateau  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

392

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

PubMed Central

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

Bento-Torres, Joao; Trevia, Nonata; de Almeida Lins, Nara Alves; Passos, Aline; Santos, Zaire; Diniz, Jose Antonio Picanco; da Costa Vasconcelos, Pedro Fernando; Cunningham, Colm; Perry, Victor Hugh; Picanco Diniz, Cristovam Wanderley

2011-01-01

393

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

NASA Astrophysics Data System (ADS)

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

Zordan, Michael D.; Leary, James F.

2009-02-01

394

Relative Contributions of Leaf-associated Microorganisms to Leaf Litter Breakdown in a Nutrient-enriched Headwater Stream  

NASA Astrophysics Data System (ADS)

Litter decomposition in streams occurs as a function of microbial and invertebrate processing, as well as abiotic factors. Abiotic factors, such as streamwater nutrient concentrations, may change the relative importance of groups of microorganisms, as well as invertebrates, to leaf breakdown. We plan to quantify the relative contributions of bacteria, fungi, and invertebrate processing on decaying leaves in a reference and treatment stream (experimentally enriched with N & P for 4.5 yrs) at the Coweeta Long Term Ecological Research site in North Carolina, USA. Leaf packs of maple or rhododendron leaves were periodically retrieved to determine decay rates. Microbial activity was measured as respiration, fungal biomass was determined by measuring ergosterol concentration, and bacterial biomass was determined by epifluorescence microscopy. Breakdown rates were dramatically faster in the nutrient enriched stream than the reference stream, associated with greater microbial activity and presumably, invertebrate feeding. Based on whole-system response by microorganisms, we predict that nutrient enrichment will lead to greater contributions of fungi, relative to bacteria, to leaf breakdown. Our results show that enrichment can fundamentally alter the rate of organic matter breakdown in streams, and will test whether enrichment also changes the relative roles of groups of organisms contributing to breakdown processes.

Tant, C. J.; Rosemond, A. D.; Taylor, N.; Conners, D. E.; Suberkropp, K.

2005-05-01

395

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.

396

Research Related to the Schoolwide Enrichment Triad Model.  

ERIC Educational Resources Information Center

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

Renzulli, Joseph S.; Reis, Sally M.

1994-01-01

397

Twenty percent hydrogen-enriched natural gas transient performance research  

Microsoft Academic Search

In order to increase engine transient performance of 20% hydrogen-enriched natural gas, research including the comparing of ETC cycle emissions in different catalysts, different enrichment rates, and data was taken for both 20% HCNG and pure natural gas. The exhaust composition and efficiency was tested using three different oxidization catalysts: ECOCAT type I, a Domestic catalysts, and ECOCAT typeII. Using

Fanhua Ma; Yefu Wang; Shangfen Ding; Long Jiang

2009-01-01

398

STUDY OF ALTERNATIVE CONTROL MEASURES FOR SMALL CENTRIFUGE ENRICHMENT FACILITIES  

Microsoft Academic Search

The safeguards objectives for enrichment facilities are the detection of the diversion of declared nuclear material and of facility misuse. The safeguard approach currently applied for commercial centrifuge enrichment facilities are based on the Hexapartite Project. However in the case of small centrifuge plants, limited inventories and restricted visual access to the cascades, the misuse scenarios seems to overcome the

Marco A. Marzo; Hugo E. Vicens; Orpet M. Peixoto; Horacio Lee Gonzales

399

Opting for Assets to Enrich Pre-School Learning  

ERIC Educational Resources Information Center

|This research entailed an ethnographic study that sought assets and resources to enrich pre-school learning in a community challenged by poverty. The aim of this research was to identify personal and environmental assets that could be used to enrich pre-school learning within this context--instead of focusing on needs and deficiencies. The assets…

Eloff, I.; de Wet, A.

2009-01-01

400

A review of environmental enrichment for kennelled dogs, Canis familiaris  

Microsoft Academic Search

Domestic dogs can be housed in a variety of confined conditions, including kennels, shelters and laboratories. Concern over the well-being of dogs housed in human care has prompted much research in recent years into the enrichment of environments for kennelled dogs. This paper highlights the findings and recommendations arising from this work. Two types of general enrichment method are discussed,

Deborah L. Wells

2004-01-01

401

Availability of enriched isotopic material for accelerator targets  

SciTech Connect

The electromagnetic isotope enrichment facility at ORNL provides a broad spectrum of highly enriched stable isotopes to the worldwide scientific community. The continued timely availability of these materials is of vital importance in many areas of basic research and, in particular, as source material for the fabrication of accelerator targets. A brief description of the facility and its capabilities and limitations is presented.

Newman, E.

1982-01-01

402

Functional properties of pasta enriched with variable cereal brans.  

PubMed

To explore the potentiality of cereal brans for preparation of fiber enriched pasta, various cereal brans (Wheat, Rice, Barley and Oat) were added at 0, 5, 10, 15, 20 and 25 per cent to durum wheat semolina. The effect of cereal bran enrichment on the colour, cooking, sensory quality and shelf life of enriched pasta was assessed at ambient temperature. Pasta prepared with added fiber at 25 per cent level had the highest protein and dietary fiber content as compared to control. Enrichment with variable fiber sources improved the brightness of pasta, as colour of pasta enhanced significantly. Addition of cereal brans resulted an increase in the water absorption and cooking losses of pasta. This effect was dependent on the level and type of cereal brans. Significant correlation (r?=?0.80) was obtained between water absorption and volume expansion in all types of bran enriched pasta. At 25 per cent level of supplementation, maximum solids were leached into cooking water. Bran enriched pasta required less cooking time for complete gelatinization of starch. Increasing level of cereal brans had significantly affected the overall acceptability of enriched pasta. Cooking quality of pasta remained constant during storage. Non significant effect of storage was found on water activity, free fatty acids. Enriched pasta (15 per cent level of wheat, rice and oat bran and 10 per cent barley bran) was highly acceptable upto 4 months of storage with respect to quality. PMID:23904655

Kaur, Gurkirat; Sharma, Savita; Nagi, H P S; Dar, Basharat N

2011-02-25

403

21 CFR 139.115 - Enriched macaroni products.  

Code of Federal Regulations, 2010 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of any of the...

2009-04-01

404

21 CFR 139.155 - Enriched noodle products.  

Code of Federal Regulations, 2010 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of any of the...

2010-04-01

405

21 CFR 139.115 - Enriched macaroni products.  

Code of Federal Regulations, 2010 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of any of the...

2010-04-01

406

21 CFR 139.155 - Enriched noodle products.  

Code of Federal Regulations, 2010 CFR

...any substance referred to in paragraphs (a) (1), (2), and (3) of this section through the use of dried yeast, dried torula yeast, partly defatted wheat germ, enriched farina, or enriched flour, or through the direct additions of any of the...

2009-04-01

407

Surface enrichment and trace-element uptake during crystal growth  

Microsoft Academic Search

Adsorption or enrichment of trace elements in the near-surface or interfacial regions of minerals has been documented in systems ranging from low-temperature aqueous environments to magmas. Under static conditions, this surface enrichment results from chemical equilibrium between the host medium of the crystal and the surface layer, which may exhibit diversity or flexibility in the types of atomic sites present.

E. Bruce Watson

1996-01-01

408

COMPLETIONS OF NON-SYMMETRIC METRIC SPACES VIA ENRICHED CATEGORIES  

Microsoft Academic Search

It is known from (13) that nonsymmetric metric spaces corre- spond to enrichments over the monoidal closed category (0;1). We use enriched category theory and in particular a generic notion of ?atness to describe various completions for these spaces. We characterise the weights of colimits commuting in the base category (0;1) with the conical termi- nal object and cotensors. Those

VINCENT SCHMITT

2009-01-01

409

Opting for Assets to Enrich Pre-School Learning  

ERIC Educational Resources Information Center

This research entailed an ethnographic study that sought assets and resources to enrich pre-school learning in a community challenged by poverty. The aim of this research was to identify personal and environmental assets that could be used to enrich pre-school learning within this context--instead of focusing on needs and deficiencies. The assets…

Eloff, I.; de Wet, A.

2009-01-01

410

Contaminant enrichment and properties of soil adhering to skin  

Microsoft Academic Search

The adhesion of contaminated soil to skin has potentially important health implications, because the contaminants may ultimately be ingested or absorbed through the skin. Previous studies indicated that the adhering soil is enriched in contaminant concentration relative In the original soil because of the selective adhesion of finer particles. This study investigated this enrichment using 11 markedly different soils. Two

S. C. Sheppard; W. G. Evenden

1994-01-01

411

PRODUCTION OF LOW ENRICHMENT URANIUM FUEL ELEMENT CORES  

Microsoft Academic Search

Reduction of enriched gaseous uranium hexafluoride to uranium ; tetrafluoride with dissociated ammonia, reduction of uranium testrafluoride to ; metal with magnesium metal, vacuum casting of uranium ingots, and subsequent ; fabrication steps such as swaging and re other aspects of production such as: the ; reclamation and direct recycle of enriched metallic residues by the technique of ; atmospheric

F. L. Cuthbert; C. E. Crompton; J. O. Davis; C. E. Polson

1958-01-01

412

Results from the international evaluation exercise for uranium enrichment measurements  

Microsoft Academic Search

An international evaluation exercise for uranium enrichment measurement was organized by the ESARDA (European Safeguards Research and Development Association) Working Group on Techniques and Standards for Non-Destructive Analysis. The aim of this exercise was to test the different methods and more particularly X- and ?-ray spectrometry methods used in the determination of uranium enrichment. Sets of samples of different uranium

J Morel; C Hill; M Bickel; A Alonso-Munoz; S Napier; B Thaurel

2000-01-01

413

Minor isotope measurements for safeguarding a uranium enrichment plant  

Microsoft Academic Search

A study of the behavior of the minor uranium isotopes in enrichment cascades indicates that the measurement of their concetrations in cascade feed and withdrawal streams can be used to confirm or deny material accountability results in safeguarding an enrichment plant. In further support of safeguard measures, an indirect non-intrusive method to measure cascade uranium inventory has been devised and

S. Blumkin; S. A. Levin; E. Von Halle

1979-01-01

414

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

415

Degradation of p-xylene by a denitrifying enrichment culture.  

PubMed Central

Microbial cultures enriched from a diesel fuel-contaminated aquifer were able to grow on p-xylene under denitrifying conditions. The oxidation of p-xylene to CO2 was coupled to the reduction of NO3-. The enrichment cultures also grew on toluene and m-xylene, but they did not degrade benzene, ethylbenzene, and o-xylene.

Haner, A; Hohener, P; Zeyer, J

1995-01-01

416

Enriched Video Semantic Metadata: Authorization, Integration, and Presentation.  

ERIC Educational Resources Information Center

|Presents an enriched video metadata framework including video authorization using the Video Annotation and Summarization Tool (VAST)-a video metadata authorization system that integrates both semantic and visual metadata-- metadata integration, and user level applications. Results demonstrated that the enriched metadata were seamlessly…

Mu, Xiangming; Marchionini, Gary

2003-01-01

417

3D reconstruction and enrichment of broadcast soccer video  

Microsoft Academic Search

Recently, it has become a new trend to reconstruct sports video for various purposes. This paper presents a 3D reconstruction and enrichment system that not only reconstructs broadcast soccer video but also enriches reconstructed video with music and illustrations of the video contents. The system can reconstruct not only the goalmouth scene but also the midfield scene, which cannot be

Xinguo Yu; Xin Yan; Tze Sen Hay; Hon Wai Leong

2004-01-01

418

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

419

Is chlorophyll-a the best surrogate for organic matter enrichment in submicron primary marine aerosol?  

NASA Astrophysics Data System (ADS)

Initial efforts toward developing a combined organic-inorganic sea spray source function parameterization for large-scale models made use of chlorophyll-a (Chl-a) and wind speed as input parameters to combine oceanic biology and atmospheric dynamics. These studies reported a modest correlation coefficient (0.55) between chlorophyll-a and organic matter (OM) enrichment in sea spray, suggesting that chlorophyll-a is only partially suitable for predicting organic enrichment. A reconstructed chlorophyll-a field of the North Atlantic Ocean from GlobColour reveals an improved correlation of 0.72 between the fractional mass contribution of organics in sea spray and chlorophyll-a concentration. A similar analysis, using colored dissolved and detrital organic material absorption and particulate organic carbon concentration, revealed slightly lower correlation coefficients (0.65 and 0.68). These results indicate that to date, chlorophyll-a is the best biological surrogate for predicting sea spray organic enrichment. In fact, considering the minimal difference between the correlation coefficients obtained with the three ocean color products, there is no reason to substitute chlorophyll-a, which is the most accurate parameter obtained from ocean color data, with other biological surrogates being generally affected by larger and less known errors. The observed time lag between chlorophyll-a concentration and organic matter enrichment in aerosol suggests that biological processes in oceanic surface waters and their timescales should be considered when modeling the production of primary marine organic aerosol.

Rinaldi, Matteo; Fuzzi, Sandro; Decesari, Stefano; Marullo, Salvatore; Santoleri, Rosalia; Provenzale, Antonello; Hardenberg, Jost; Ceburnis, Darius; Vaishya, Aditya; O'Dowd, Colin D.; Facchini, Maria Cristina

2013-05-01

420

Atmospheric mercury emissions from mine wastes and surrounding geologically enriched terrains  

SciTech Connect

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 {micro}g Hg g{sup -1}). Mercury fluxes to the atmosphere from mineralized areas can range from background rates (0-15 ng m{sup -2} h{sup -1}) to tens of thousands of ng m{sup -2} h{sup -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 western United States volatilization is the primary means by which mercury is released from enriched sites.

Gustin, Mae S. [University of Nevada, Reno; Coolbaugh, M. F. [University of Nevada, Reno; Engle, M. A. [University of Nevada, Reno; Fitzgerald, B. C. [University of Nevada, Reno; Keislar, R. E. [Desert Research Institute, Reno, NV; Lindberg, Steven Eric [ORNL; Nacht, D. M. [University of Nevada, Reno; Quashnick, J. [University of Nevada, Reno; Rytuba, J. J. [U.S. Geological Survey, Menlo Park, CA; Sladek, C. [University of Nevada, Reno; Zhang, Hong [ORNL; Zehner, R. E. [University of Nevada, Reno

2003-01-01

421

Photochemical Enrichment of Deuterium in Titan's Atmosphere: New Insights from Cassini-Huygens  

NASA Astrophysics Data System (ADS)

Cassini-Huygens data are used to reexamine the potential sources of the D/H enhancement over solar, measured in methane, in Titan's atmosphere. Assuming that the system is closed with respect to carbon, the use of constraints from the Huygens probe for the determination of the current mass of atmospheric methane and the most up-to-date determination of D/H from Cassini CIRS infrared spectra allow us to show that photochemical enrichment of deuterium is not sufficient to be the sole mechanism yielding the measured D/H value. A possible fractionation between CH3D and CH4 during the escape process may slightly enhance the deuterium enrichment, but is not sufficient to explain the observed D/H value over the range of escape values proposed in the literature. Hence, alternative mechanisms such as a primordial deuterium enrichment must be combined with the photochemical enrichment in Titan's atmosphere in order to explain its current D/H value.

Cordier, Daniel; Mousis, Olivier; Lunine, Jonathan I.; Moudens, Audrey; Vuitton, Véronique

2008-12-01

422

New Constraints on Photochemical Enrichment of Deuterium in Titan's Atmosphere from Cassini-huygens Data  

NASA Astrophysics Data System (ADS)

Cassini-Huygens data are used to re-examine the potential sources of the D/H enhancement over solar, measured in methane, in Titan's atmosphere. Assuming that the system is closed with respect to carbon, the use of constraints from the Huygens probe for the determination of the current mass of atmospheric methane and the most up-to-date determination of D/H from Cassini/CIRS infrared spectra allow us to show that photochemical enrichment of deuterium is not sufficient to be the sole mechanism yielding the measured D/H value. A possible fractionation between CH3D and CH4 during the escape process may slightly enhance the deuterium enrichment, but is not sufficient to explain the observed D/H value over the range of escape values proposed in the literature. Hence, alternative mechanisms such as a primordial deuterium enrichment must be combined with the photochemical enrichment in Titan's atmosphere in order to explain its current D/H value.

Cordier, Daniel; Mousis, O.; Lunine, J.; Moudens, A.; Vuitton, V.

2008-09-01

423

Ti(4+)-phosphate functionalized cellulose for phosphopeptides enrichment and its application in rice phosphoproteome analysis.  

PubMed

In this study, a novel immobilized metal ion affinity chromatography (IMAC) material for phosphopeptide enrichment was prepared based on modified cellulose and was applied in rice phosphoproteome analysis. Firstly, cellulose was modified with phosphoric acid via esterification, and then Ti(4+) was chelated onto the phosphorylated cellulose. The synthesized materials were ultrafine powders and had good dispersibility in acidic buffer, and as supporting matrix, phosphorylated cellulose exhibited good biocompatibility and chemical stability. Enrichment conditions were optimized and the optimum loading buffer was 40% acetonitrile (ACN) with 6% trifluoroacetic acid (TFA). Finally, the Ti(4+)-phosphate functionalized cellulose was submitted to phosphopeptides enrichment prior to mass spectrometry (MS). For ?-casein lysates, 14 phosphopeptides were detected with high intensities even though the sample concentration was as low as 2 pmol. Besides, 15 phosphopeptides were still identified by using the digest mixture of ?-casein and bovine serum albumin with molar ratio of 1:100, which demonstrated high specificity and sensitivity for phosphopeptides enrichment. 19 phosphoproteins were identified from 200 ?g of salt-free rice leaf protein lysates, while 30 phosphoproteins were identified from salt-stressed rice leaf protein lysates, and most of these proteins were related to the biological processes in response to abiotic stimulus. PMID:22795554

Shen, Feng; Hu, Yufeng; Guan, Ping; Ren, Xueqin

2012-07-01

424

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; Zevenbergen, Lee [ORNL

2013-01-01

425

Light-responsive current generation by phototrophically enriched anode biofilms dominated by green sulfur bacteria.  

PubMed

The objective of this study was to employ microbial electrochemical cells (MXCs) to selectively enrich and examine anoxygenic photosynthetic bacteria for potential anaerobic respiration capabilities using electrodes. In the process, we designed a novel enrichment strategy that manipulated the poised anode potential, light, nitrogen availability, and media supply to promote growth of phototrophic bacteria while minimizing co-enrichment of non-phototrophic anode-respiring bacteria (ARB). This approach resulted in light-responsive electricity generation from fresh- and saltwater inocula. Under anoxic conditions, current showed a negative light response, suggesting that the enriched phototrophic consortia shifted between phototrophic and anaerobic respiratory metabolism. Molecular, physical, and electrochemical analyses elucidated that anode biofilms were dominated by green sulfur bacteria, and biofilms exhibited anode respiration kinetics indicative of non-mediated electron transfer, but kinetic parameters differed from values previously reported for non-phototrophic ARB. These results invite the utilization of MXCs as microbiological tools for exploring anaerobic respiratory capabilities among anoxygenic photosynthetic bacteria. PMID:23124549

Badalamenti, Jonathan P; Torres, César I; Krajmalnik-Brown, Rosa

2012-11-23

426

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

SciTech Connect

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

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

2008-06-05

427

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

428

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

2013-09-19

429

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

430

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

431

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

SciTech Connect

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

Lu Swan, Delta Ferrites LLC

2009-09-30

432

Enrichment and Site Mapping of O-Linked N-Acetylglucosamine by a Combination of Chemical/Enzymatic Tagging, Photochemical Cleavage, and Electron Transfer Dissociation Mass Spectrometry*  

PubMed Central

Numerous cellular processes are regulated by the reversible addition of either phosphate or O-linked ?-N-acetylglucosamine (O-GlcNAc) to nuclear and cytoplasmic proteins. Although sensitive methods exist for the enrichment and identification of protein phosphorylation sites, those for the enrichment of O-GlcNAc-containing peptides are lacking. Reported here is highly efficient methodology for the enrichment and characterization of O-GlcNAc sites from complex samples. In this method, O-GlcNAc-modified peptides are tagged with a novel biotinylation reagent, enriched by affinity chromatography, released from the solid support by photochemical cleavage, and analyzed by electron transfer dissociation mass spectrometry. Using this strategy, eight O-GlcNAc sites were mapped from a tau-enriched sample from rat brain. Sites of GlcNAcylation were characterized on important neuronal proteins such as tau, synucleins, and methyl CpG-binding protein 2.

Wang, Zihao; Udeshi, Namrata D.; O'Malley, Meaghan; Shabanowitz, Jeffrey; Hunt, Donald F.; Hart, Gerald W.

2010-01-01

433

Opportunistic pathogens enriched in showerhead biofilms  

PubMed Central

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

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

2009-01-01

434

Identification, Selection, and Enrichment of Cardiomyocyte Precursors  

PubMed Central

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.

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

2013-01-01

435

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

Microsoft Academic Search

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

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

2010-01-01

436

Localization of RhoA GTPase to Endothelial Caveolae-Enriched Membrane Domains  

Microsoft Academic Search

Caveolae are small microdomains of the plasma membrane that are thought to play important roles in signal transduction processes. In this work, we have investigated the association of Rho proteins with caveolae-enriched membrane domains isolated from cultured endothelial cells. Fractionation of ECV304 cells by sucrose gradient density centrifugation in the absence of detergent resulted in the co-sedimentation of a significant

Denis Gingras; France Gauthier; Sylvie Lamy; Richard R. Desrosiers; Richard Béliveau

1998-01-01

437

Transport of Newly Synthesized Sterol to the Sterol-Enriched Plasma Membrane Occurs via Nonvesicular Equilibration †  

Microsoft Academic Search

The mechanism by which newly synthesized sterols are transported from their site of synthesis, the endoplasmic reticulum (ER), to the sterol-enriched plasma membrane (PM) is not fully understood. Studies in mammalian cells suggest that newly synthesized cholesterol is transported to the PM in Golgi- bypassing vesicles and\\/or via a nonvesicular process. Using the yeast Saccharomyces cereVisiae as a model system,

Nikola A. Baumann; David P. Sullivan; Henna Ohvo-Rekilä; Cedric Simonot; Anita Pottekat; Zachary Klaassen; Christopher T. Beh; Anant K. Menon

2005-01-01

438

Optimal step assays and flow rates in gaseous diffusion squared-off cascades for uranium enrichment  

Microsoft Academic Search

Optimal step assays and interstage up-flow rates for enriching and stripping sections of uranium gaseous diffusion squared-off cascades are manageably determined without any additional approximations beyond the usual ones (i.e., a close separation process and a constant cut in the whole section). This is accomplished by the application of the optimization conditions to the function to be minimized, i.e., the

O. Fiorella; M. Mangia; E. Oliveri

1983-01-01

439

Comparison of five methods for assessing impacts of nutrient enrichment using estuarine case studies  

Microsoft Academic Search

There are several approaches for assessing nutrient enrichment impacts in marine waters including the OSPAR* Comprehensive\\u000a Procedure, the TRIX* ranking process, the WFD, ASSETS* and EPA NCA*. They differ in definitions and application, but all use\\u000a key indicators for evaluating eutrophication status. Data from two estuaries in the United Kingdom (UK) were used to test\\u000a the hypothesis that these five

Michelle Devlin; Suzanne Bricker; Suzanne Painting

440

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

Microsoft Academic Search

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

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

2011-01-01

441

Verification of Uranium Mass and Enrichments of Highly Enriched Uranium (HEU) Using the Nuclear Materials Identification System (NMIS)  

Microsoft Academic Search

This paper describes how the Nuclear Materials Identification System (NMIS), developed by the Oak Ridge National Laboratory (ORNL) and the Oak Ridge Y-12 Plant, was used to verify the mass and enrichment of hundreds of Highly Enriched Uranium (HEU) metal items in storage at the Y-12 Plant. The verifications had a relative spread of {+-}5% (3 sigma) with relative mean

L. G. Chiang; J. K. Mattingly; J. A. Ramsey; J. T. Mihalczo

2000-01-01

442

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

NASA Astrophysics Data System (ADS)

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

Kuhn, N. J.

2012-04-01

443

P189-T IMAC Enrichment of Phosphopeptides Coupled with 18O Labeling: Quantitative Phosphoproteomics  

PubMed Central

The up- and down-regulation of protein expression has long been a focus of proteomics researchers and has given rise to several mass spectrometry–based quantitation techniques. In the past decade, a great deal of attention has turned toward the subproteomes, particularly those representing post-translational modifications (PTMs), such as phosphorylation. Those PTMs often play key roles in signaling cascades, and affect a number of cellular processes; their study offers insight into intracellular function. We illustrate here phosphoproteome quantitation through the pairing of immobilized metal-affinity chromatography (IMAC) and 18O labeling, which allows for the determination of modulated phosphorylated species in response to external stressors. Following application of varying biological stressors and isolation of each resultant proteome, the samples were proteolytically cleaved using immobilized trypsin. IMAC enrichment of phosphorylated peptides was accomplished using a nitrilotriacetic acid (NTA) analog bonded to silica, presenting Ga3+ as the chelated metal species. Immobilized trypsin was also employed for incorporation of 18O into the sample for quantitative global labeling. It was determined that IMAC enrichment utilizing this combination of chelate, substrate, and metal provided significant enrichment of phosphopeptides that afforded signal levels, which allowed for quantitative analysis of the phosphoproteome. The use of 18O labeling of the samples permitted a global approach to targeting the phosphoproteome concurrent with the non-phosphorylated component. Using MS analysis before and after IMAC-based phosphopeptide enrichment revealed a distinction in regulation of expression and modulation through phosphorylation of the proteins. The coupling of phosphopeptide enrichment with global isotopic labeling provides a valuable and enabling resource for the vastly under-explored area of quantitative phosphoproteomics.

Turner, J. L.; Walters, J. J.; Heutel, J. D.; Radwanski, B. K.; Boland, J.; Ray, K.; Dapron, J. G.

2007-01-01

444

Robust phosphoproteome enrichment using monodisperse microsphere-based immobilized titanium (IV) ion affinity chromatography.  

PubMed

Mass spectrometry (MS)-based proteomics has become the preferred tool for the analysis of protein phosphorylation. To be successful at such an endeavor, there is a requirement for an efficient enrichment of phosphopeptides. This is necessary because of the substoichiometric nature of phosphorylation at a given site and the complexity of the cell. Recently, new alternative materials have emerged that allow excellent and robust enrichment of phosphopeptides. These monodisperse microsphere-based immobilized metal ion affinity chromatography (IMAC) resins incorporate a flexible linker terminated with phosphonate groups that chelate either zirconium or titanium ions. The chelated zirconium or titanium ions bind specifically to phosphopeptides, with an affinity that is similar to that of other widely used metal oxide affinity chromatography materials (typically TiO(2)). Here we present a detailed protocol for the preparation of monodisperse microsphere-based Ti(4+)-IMAC adsorbents and the subsequent enrichment process. Furthermore, we discuss general pitfalls and crucial steps in the preparation of phosphoproteomics samples before enrichment and, just as importantly, in the subsequent mass spectrometric analysis. Key points such as lysis, preparation of the chromatographic system for analysis and the most appropriate methods for sequencing phosphopeptides are discussed. Bioinformatics analysis specifically relating to site localization is also addressed. Finally, we demonstrate how the protocols provided are appropriate for both single-protein analysis and the screening of entire phosphoproteomes. It takes ?2 weeks to complete the protocol: 1 week to prepare the Ti(4+)-IMAC material, 2 d for sample preparation, 3 d for MS analysis of the enriched sample and 2 d for data analysis. PMID:23391890

Zhou, Houjiang; Ye, Mingliang; Dong, Jing; Corradini, Eleonora; Cristobal, Alba; Heck, Albert J R; Zou, Hanfa; Mohammed, Shabaz

2013-02-07

445

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

PubMed

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