Sample records for gas centrifuge enrichment

  1. Laser and gas centrifuge enrichment

    SciTech Connect (OSTI)

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

    2014-05-09T23:59:59.000Z

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

  2. THE THEORY OF URANIUM ENRICHMENT BY THE GAS CENTRIFUGE

    E-Print Network [OSTI]

    Olander, Donald R.

    2013-01-01T23:59:59.000Z

    1979) in "Uranium Enrichment", S. Villani, Ed. , Springer-E. (1973) "Uranium Enrichment by Gas Centrifuge" Mills andTHE THEORY OF URANIUM ENRICHMENT BY THE GAS CENTRIFUGE

  3. New generation enrichment monitoring technology for gas centrifuge enrichment plants

    SciTech Connect (OSTI)

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

    2008-06-13T23:59:59.000Z

    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.

  4. Gas Centrifuge Enrichment Plant Safeguards System Modeling

    SciTech Connect (OSTI)

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

    2006-06-05T23:59:59.000Z

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

  5. THE THEORY OF URANIUM ENRICHMENT BY THE GAS CENTRIFUGE

    E-Print Network [OSTI]

    Olander, Donald R.

    2013-01-01T23:59:59.000Z

    Technical Basis of the Gas Centrifuge", Adv. in Nucl. Sci.D.R. , (1978) "The Gas Centrifuge", Scientific American,Fluid Dynamics of a Gas Centrifuge", J. Fluid Mech. , 101,

  6. Defining the needs for gas centrifuge enrichment plants advanced safeguards

    SciTech Connect (OSTI)

    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; Marlow, Johnna B [Los Alamos National Laboratory

    2010-04-05T23:59:59.000Z

    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.

  7. Systems approach used in the Gas Centrifuge Enrichment Plant

    SciTech Connect (OSTI)

    Rooks, W.A. Jr.

    1982-01-01T23:59:59.000Z

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

  8. New Measures to Safeguard Gas Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    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

    2011-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Swindle, D.W.

    1990-03-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2012-09-26T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Not Available

    1988-10-01T23:59:59.000Z

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

  13. RADIO FREQUENCY IDENTIFICATION DEVICES: EFFECTIVENESS IN IMPROVING SAFEGUARDS AT GAS-CENTRIFUGE URANIUM-ENRICHMENT PLANTS.

    SciTech Connect (OSTI)

    JOE,J.

    2007-07-08T23:59:59.000Z

    Recent advances in radio frequency identification devices (RFIDs) have engendered a growing interest among international safeguards experts. Potentially, RFIDs could reduce inspection work, viz. the number of inspections, number of samples, and duration of the visits, and thus improve the efficiency and effectiveness of international safeguards. This study systematically examined the applications of RFIDs for IAEA safeguards at large gas-centrifuge enrichment plants (GCEPs). These analyses are expected to help identify the requirements and desirable properties for RFIDs, to provide insights into which vulnerabilities matter most, and help formulate the required assurance tests. This work, specifically assesses the application of RFIDs for the ''Option 4'' safeguards approach, proposed by Bruce Moran, U. S. Nuclear Regulatory Commission (NRC), for large gas-centrifuge uranium-enrichment plants. The features of ''Option 4'' safeguards include placing RFIDs on all feed, product and tails (F/P/T) cylinders, along with WID readers in all FP/T stations and accountability scales. Other features of Moran's ''Option 4'' are Mailbox declarations, monitoring of load-cell-based weighing systems at the F/P/T stations and accountability scales, and continuous enrichment monitors. Relevant diversion paths were explored to evaluate how RFIDs improve the efficiency and effectiveness of safeguards. Additionally, the analysis addresses the use of RFIDs in conjunction with video monitoring and neutron detectors in a perimeter-monitoring approach to show that RFIDs can help to detect unidentified cylinders.

  14. Analysis of the effectiveness of gas centrifuge enrichment plants advanced safeguards

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    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.

    2010-09-13T23:59:59.000Z

    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.

  16. FEMO, A FLOW AND ENRICHMENT MONITOR FOR VERIFYING COMPLIANCE WITH INTERNATIONAL SAFEGUARDS REQUIREMENTS AT A GAS CENTRIFUGE ENRICHMENT FACILITY

    SciTech Connect (OSTI)

    Gunning, John E [ORNL; Laughter, Mark D [ORNL; March-Leuba, Jose A [ORNL

    2008-01-01T23:59:59.000Z

    A number of countries have received construction licenses or are contemplating the construction of large-capacity gas centrifuge enrichment plants (GCEPs). The capability to independently verify nuclear material flows is a key component of international safeguards approaches, and the IAEA does not currently have an approved method to continuously monitor the mass flow of 235U in uranium hexafluoride (UF6) gas streams. Oak Ridge National Laboratory is investigating the development of a flow and enrichment monitor, or FEMO, based on an existing blend-down monitoring system (BDMS). The BDMS was designed to continuously monitor both 235U mass flow and enrichment of UF6 streams at the low pressures similar to those which exists at GCEPs. BDMSs have been installed at three sites-the first unit has operated successfully in an unattended environment for approximately 10 years. To be acceptable to GCEP operators, it is essential that the instrument be installed and maintained without interrupting operations. A means to continuously verify flow as is proposed by FEMO will likely be needed to monitor safeguards at large-capacity plants. This will enable the safeguards effectiveness that currently exists at smaller plants to be maintained at the larger facilities and also has the potential to reduce labor costs associated with inspections at current and future plants. This paper describes the FEMO design requirements, operating capabilities, and development work required before field demonstration.

  17. Gas Centrifuges and Nuclear Proliferation

    SciTech Connect (OSTI)

    Albright, David

    2004-09-15T23:59:59.000Z

    Gas centrifuges have been an ideal enrichment method for a wide variety of countries. Many countries have built gas centrifuges to make enriched uranium for peaceful nuclear purposes. Other countries have secretly sought centrifuges to make highly enriched uranium for nuclear weapons. In more recent times, several countries have secretly sought or built gas centrifuges in regions of tension. The main countries that have been of interest in the last two decades have been Pakistan, Iraq, Iran, and North Korea. Currently, most attention is focused on Iran, Pakistan, and North Korea. These states did not have the indigenous abilities to make gas centrifuges, focusing instead on illicit and questionable foreign procurement. The presentation covered the following main sections: Spread of centrifuges through illicit procurement; Role of export controls in stopping proliferation; Increasing the transparency of gas centrifuge programs in non-nuclear weapon states; and, Verified dismantlement of gas centrifuge programs. Gas centrifuges are important providers of low enriched uranium for civil nuclear power reactors. They also pose special nuclear proliferation risks. We all have special responsibilities to prevent the spread of gas centrifuges into regions of tension and to mitigate the consequences of their spread into the Middle East, South Asia, and North Asia.

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

    SciTech Connect (OSTI)

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

    1985-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

    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.

  20. In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    Ward,R.; Rosenthal,M.

    2009-07-12T23:59:59.000Z

    Global expansion of nuclear power has made the need for improved safeguards measures at Gas Centrifuge Enrichment Plants (GCEPs) imperative. One technology under consideration for safeguards applications is Radio Frequency Identification Devices (RFIDs). RFIDs have the potential to increase IAEA inspector"s efficiency and effectiveness either by reducing the number of inspection visits necessary or by reducing inspection effort at those visits. This study assesses the use of RFIDs as an integral component of the "Option 4" safeguards approach developed by Bruce Moran, U.S. Nuclear Regulatory Commission (NRC), for a model GCEP [1]. A previous analysis of RFIDs was conducted by Jae Jo, Brookhaven National Laboratory (BNL), which evaluated the effectiveness of an RFID tag applied by the facility operator [2]. This paper presents a similar evaluation carried out in the framework of Jo’s paper, but it is predicated on the assumption that the RFID tag is applied by the manufacturer at the birth of the cylinder, rather than by the operator. Relevant diversion scenarios are examined to determine if RFIDs increase the effectiveness and/ or efficiency of safeguards in these scenarios. Conclusions on the benefits offered to inspectors by using in-born RFID tagging are presented.

  1. Valve for gas centrifuges

    DOE Patents [OSTI]

    Hahs, C.A.; Rurbage, C.H.

    1982-03-17T23:59:59.000Z

    The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  2. Approach to IAEA verification of the nuclear-material balance at the Portsmouth Gas Centrifuge Enrichment Plant (GCEP)

    SciTech Connect (OSTI)

    Gordon, D.M.; Sanborn, J.B.; Younkin, J.M.; DeVito, V.J.

    1982-01-01T23:59:59.000Z

    This paper describes a potential approach by which the International Atomic Energy Agency (IAEA) might verify the nuclear-material balance at the Portsmouth Gas Centrifuge Enrichment Plant (GCEP), should that plant be placed under IAEA safeguards. The strategy makes use of the attributes and variables measurement verification approach, whereby the IAEA would perform independent measurements on a randomly selected subset of the items comprising the U-235 flows and inventories at the plant. In addition, the MUF-D statistic is used as the test statistics for the detection of diversion. The paper includes descriptions of the potential verification activities, as well as calculations of (a) attributes and variables sample sizes for the various strata, (b) standard deviations of the relevant test statistics, and (c) the sensitivity for detection of diversion which the IAEA might achieve by this verification strategy at GCEP.

  3. Approach to IAEA material-balance verification with intermittent inspection at the Portsmouth Gas Centrifuge Enrichment Plant

    SciTech Connect (OSTI)

    Gordon, D.M.; Sanborn, J.B.

    1984-05-18T23:59:59.000Z

    This paper describes a potential approach by which the International Atomic Energy Agency (IAEA) might verify the nuclear-material balance at the Portsmouth Gas Centrifuge Enrichment Plant (GCEP) for the circumstance in which the IAEA inspections occur on an intermittent basis. The verification approach is a variation of the standard IAEA attributes/variables measurement-verification method. This alternative approach is useful and applicable at the Portsmouth GCEP, which will ship all its product and tails UF/sub 6/ to United States facilities not eligible for IAEA safeguards. The paper reviews some of the relevant results of the Hexapartite Safeguards Project (HSP), describes the standard IAEA material-balance-verification approach for bulk-handling facilities, and provides the procedures to be followed in handling and processing UF/sub 6/ cylinders at the Portsmouth GCEP. The paper then discusses the assumptions made in the approach, and derives a formula for the probability with which the IAEA could detect the diversion of a significant quantity of uranium (75 kg of U-235 in depleted, normal, and low-enriched uranium) if this method were applied. The paper also provides numerical examples of IAEA detection probability should the operator divert uranium from the feed, product, or tails streams for the Portsmouth GCEP with a capacity of 1100 tonnes of separative work per year.

  4. Application of Condition-Based Monitoring Techniques for Remote Monitoring of a Simulated Gas Centrifuge Enrichment Plant

    SciTech Connect (OSTI)

    Hooper, David A [ORNL; Henkel, James J [ORNL; Whitaker, Michael [ORNL

    2012-01-01T23:59:59.000Z

    This paper presents research into the adaptation of monitoring techniques from maintainability and reliability (M&R) engineering for remote unattended monitoring of gas centrifuge enrichment plants (GCEPs) for international safeguards. Two categories of techniques are discussed: the sequential probability ratio test (SPRT) for diagnostic monitoring, and sequential Monte Carlo (SMC or, more commonly, particle filtering ) for prognostic monitoring. Development and testing of the application of condition-based monitoring (CBM) techniques was performed on the Oak Ridge Mock Feed and Withdrawal (F&W) facility as a proof of principle. CBM techniques have been extensively developed for M&R assessment of physical processes, such as manufacturing and power plants. These techniques are normally used to locate and diagnose the effects of mechanical degradation of equipment to aid in planning of maintenance and repair cycles. In a safeguards environment, however, the goal is not to identify mechanical deterioration, but to detect and diagnose (and potentially predict) attempts to circumvent normal, declared facility operations, such as through protracted diversion of enriched material. The CBM techniques are first explained from the traditional perspective of maintenance and reliability engineering. The adaptation of CBM techniques to inspector monitoring is then discussed, focusing on the unique challenges of decision-based effects rather than equipment degradation effects. These techniques are then applied to the Oak Ridge Mock F&W facility a water-based physical simulation of a material feed and withdrawal process used at enrichment plants that is used to develop and test online monitoring techniques for fully information-driven safeguards of GCEPs. Advantages and limitations of the CBM approach to online monitoring are discussed, as well as the potential challenges of adapting CBM concepts to safeguards applications.

  5. Valve for gas centrifuges

    DOE Patents [OSTI]

    Hahs, Charles A. (Oak Ridge, TN); Burbage, Charles H. (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  6. The gas centrifuge and nuclear weapons proliferation

    SciTech Connect (OSTI)

    Wood, Houston G. [Mechanical and Aerospace Engineering Department, University of Virginia, Charlottesville, Virginia (United States); Glaser, Alexander [Woodrow Wilson School of Public and International Affairs, Program on Science, Technology and Environmental Policy, Princeton University, Princeton, New Jersey (United States); Kemp, R. Scott [Nuclear Science and Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States)

    2014-05-09T23:59:59.000Z

    Uranium enrichment by centrifugation is the basis for the quick and efficient production of nuclear fuel-or nuclear weapons.

  7. Defining the needs for non-destructive assay of UF6 feed, product, and tails at gas centrifuge enrichment plants and possible next steps

    SciTech Connect (OSTI)

    Boyer, Brian D [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Moran, Bruce W [IAEA; Lebrun, Alain [IAEA

    2009-01-01T23:59:59.000Z

    Current safeguards approaches used by the IAEA at gas centrifuge enrichment plants (GCEPs) need enhancement in order to detect undeclared LEU production with adequate detection probability using non destructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of UF{sub 6} bulk material used in the process of enrichment at GCEPS. The inspectors also take destructive assay (DA) samples for analysis off-site which provide accurate, on the order of 0.1 % to 0.5% uncertainty, data on the enrichment of the UF{sub 6} feed, tails, and product. However, DA sample taking is a much more labor intensive 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 the results and contains the possibility of the loss of the continuity of knowledge of the samples during the storage and transit of the material. Use of the IAEA's inspection sampling algorithm shows that while total sample size is fixed by the total population of potential samples and its intrinsic qualities, the split of the samples into NDA or DA samples is determined by the uncertainties in the NDA measurements. Therefore, the larger the uncertainties in the NDA methods, more of the sample taken must be DA samples. Since the DA sampling is arduous and costly, improvements in NDA methods would reduce the number of DA samples needed. Furthermore, if methods of on-site analysis of the samples could be developed that have uncertainties in the 1-2% range, a lot of the problems inherent in DA sampling could be removed. The use of an unattended system that could give an overview of the entire process giving complementary data on the enrichment process as well as accurate measures of enrichment and weights of the UF{sub 6} feed, tails, and product would be a major step in enhancing the ability of NDA beyond present attended systems. The possibility of monitoring the feed, tails, and product header pipes in such a way as to gain safeguards relevant flow and enrichment information without compromising the intellectual property of the operator including proprietary equipment and operational parameters would be a huge step forward. This paper contains an analysis of possible improvements in unattended and attended NDA systems including such process monitoring and possible on-site analysis of DA samples that could reduce the uncertainty of the inspector measurements reducing the difference between the operator's and inspector's measurements providing more effective and efficient IAEA GeEPs safeguards.

  8. USE OF MAILBOX APPROACH, VIDEO SURVEILLANCE, AND SHORT-NOTICE RANDOM INSPECTIONS TO ENHANCE DETECTION OF UNDECLARED LEU PRODUCTION AT GAS CENTRIFUGE ENRICHMENT PLANTS.

    SciTech Connect (OSTI)

    BOYER, B.D.; GORDON, D.M.; JO, J.

    2006-07-16T23:59:59.000Z

    Current safeguards approaches used by the IAEA at gas centrifuge enrichment plants (GCEPs) need enhancement in order to detect undeclared LEU production with adequate detection probability. ''Mailbox'' declarations have been used in the last two decades to verify receipts, production, and shipments at some bulk-handling facilities (e.g., fuel-fabrication plants). The operator declares the status of his plant to the IAEA on a daily basis using a secure ''Mailbox'' system such as a secure tamper-resistant computer. The operator agrees to hold receipts and shipments for a specified period of time, along with a specified number of annual inspections, to enable inspector access to a statistically large enough population of UF{sub 6} cylinders and fuel assemblies to achieve the desired detection probability. The inspectors can access the ''Mailbox'' during randomly timed inspections and then verify the operator's declarations for that day. Previously, this type of inspection regime was considered mainly for verifying the material balance at fuel-fabrication, enrichment, and conversion plants. Brookhaven National Laboratory has expanded the ''Mailbox'' concept with short-notice random inspections (SNRIs), coupled with enhanced video surveillance, to include declaration and verification of UF{sub 6} cylinder operational data to detect activities associated with undeclared LEU production at GCEPs. Since the ''Mailbox'' declarations would also include data relevant to material-balance verification, these randomized inspections would replace the scheduled monthly interim inspections for material-balance purposes; in addition, the inspectors could simultaneously perform the required number of Limited-Frequency Unannounced Access (LFUA) inspections used for HEU detection. This approach would provide improved detection capabilities for a wider range of diversion activities with not much more inspection effort than at present.

  9. The American Gas Centrifuge Past, Present, and Future

    SciTech Connect (OSTI)

    Waters, Dean

    2004-09-15T23:59:59.000Z

    The art of gas centrifugation was born in 1935 at the University of Virginia when Dr. Jesse Beams demonstrated experimentally the separation of chlorine isotopes using an ultra-high speed centrifuge. Dr. Beam’s experiment initiated work that created a rich history of scientific and engineering accomplishment in the United States in the art of isotope separation and even large scale biological separation by centrifugation. The early history of the gas centrifuge development was captured in a lecture and documented by Dr. Jesse Beams in 1975. Much of Dr. Beams lecture material is used in this paper up to the year 1960. Following work by Dr. Gernot Zippe at the University of Virginia between 1958 and 1960, the US government embarked on a centrifuge development program that ultimately led to the start of construction of the Gas Centrifuge Enrichment Plant in Piketon Ohio in the late 1970’s. The government program was abandoned in 1985 after investing in the construction of two of six planned process buildings, a complete supply chain for process and centrifuge parts, and the successful manufacture and brief operation of an initial complement of production machines that would have met 15 percent of the planned capacity of the constructed process buildings. A declining market for enriched uranium, a glut of uranium enrichment capacity worldwide, and the promise of a new laser based separation process factored in the decision to stop the government program. By the late 1990’s it had become evident that gas centrifugation held the best promise to produce enriched uranium at low cost. In1999, the United States Enrichment Corporation undertook an initiative to revive the best of the American centrifuge technology that had been abandoned fourteen years earlier. This is an exciting story and one that when complete will enable the United States to maintain its domestic supply and to be highly competitive in the world market for this important energy commodity. (auth)

  10. Next Generation Safeguards Initiative: Analysis of Probability of Detection of Plausible Diversion Scenarios at Gas Centrifuge Enrichment Plants Using Advanced Safeguards

    SciTech Connect (OSTI)

    Hase, Kevin R. [Los Alamos National Laboratory; Hawkins Erpenbeck, Heather [Los Alamos National Laboratory; Boyer, Brian D. [Los Alamos National Laboratory

    2012-07-10T23:59:59.000Z

    Over the last decade, efforts by the safeguards community, including inspectorates, governments, operators and owners of centrifuge facilities, have given rise to new possibilities for safeguards approaches in enrichment plants. Many of these efforts have involved development of new instrumentation to measure uranium mass and uranium-235 enrichment and inspection schemes using unannounced and random site inspections. We have chosen select diversion scenarios and put together a reasonable system of safeguards equipment and safeguards approaches and analyzed the effectiveness and efficiency of the proposed safeguards approach by predicting the probability of detection of diversion in the chosen safeguards approaches. We analyzed the effect of redundancy in instrumentation, cross verification of operator instrumentation by inspector instrumentation, and the effects of failures or anomalous readings on verification data. Armed with these esults we were able to quantify the technical cost benefit of the addition of certain instrument suites and show the promise of these new systems.

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

    SciTech Connect (OSTI)

    Not Available

    1994-03-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    NONE

    1993-09-01T23:59:59.000Z

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

  13. LISSAT Analysis of a Generic Centrifuge Enrichment Plant

    SciTech Connect (OSTI)

    Lambert, H; Elayat, H A; O?Connell, W J; Szytel, L; Dreicer, M

    2007-05-31T23:59:59.000Z

    The U.S. Department of Energy (DOE) is interested in developing tools and methods for use in designing and evaluating safeguards systems for current and future plants in the nuclear power fuel cycle. The DOE is engaging several DOE National Laboratories in efforts applied to safeguards for chemical conversion plants and gaseous centrifuge enrichment plants. As part of the development, Lawrence Livermore National Laboratory has developed an integrated safeguards system analysis tool (LISSAT). This tool provides modeling and analysis of facility and safeguards operations, generation of diversion paths, and evaluation of safeguards system effectiveness. The constituent elements of diversion scenarios, including material extraction and concealment measures, are structured using directed graphs (digraphs) and fault trees. Statistical analysis evaluates the effectiveness of measurement verification plans and randomly timed inspections. Time domain simulations analyze significant scenarios, especially those involving alternate time ordering of events or issues of timeliness. Such simulations can provide additional information to the fault tree analysis and can help identify the range of normal operations and, by extension, identify additional plant operational signatures of diversions. LISSAT analyses can be used to compare the diversion-detection probabilities for individual safeguards technologies and to inform overall strategy implementations for present and future plants. Additionally, LISSAT can be the basis for a rigorous cost-effectiveness analysis of safeguards and design options. This paper will describe the results of a LISSAT analysis of a generic centrifuge enrichment plant. The paper will describe the diversion scenarios analyzed and the effectiveness of various safeguards systems alternatives.

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

    SciTech Connect (OSTI)

    Not Available

    1992-09-01T23:59:59.000Z

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

  15. Onsite Gaseous Centrifuge Enrichment Plant UF6 Cylinder Destructive Analysis

    SciTech Connect (OSTI)

    Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong (Amy) [Amy; Carter, Jennifer C.; McNamara, Bruce K.; O'Hara, Matthew J.; Phillips, Jon R.; Curtis, Michael M.

    2012-07-17T23:59:59.000Z

    The IAEA safeguards approach for gaseous centrifuge enrichment plants (GCEPs) includes measurements of gross, partial, and bias defects in a statistical sampling plan. These safeguard methods consist principally of mass and enrichment nondestructive assay (NDA) verification. Destructive assay (DA) samples are collected from a limited number of cylinders for high precision offsite mass spectrometer analysis. DA is typically used to quantify bias defects in the GCEP material balance. Under current safeguards measures, the operator collects a DA sample from a sample tap following homogenization. The sample is collected in a small UF6 sample bottle, then sealed and shipped under IAEA chain of custody to an offsite analytical laboratory. Current practice is expensive and resource intensive. We propose a new and novel approach for performing onsite gaseous UF6 DA analysis that provides rapid and accurate assessment of enrichment bias defects. DA samples are collected using a custom sampling device attached to a conventional sample tap. A few micrograms of gaseous UF6 is chemically adsorbed onto a sampling coupon in a matter of minutes. The collected DA sample is then analyzed onsite using Laser Ablation Absorption Ratio Spectrometry-Destructive Assay (LAARS-DA). DA results are determined in a matter of minutes at sufficient accuracy to support reliable bias defect conclusions, while greatly reducing DA sample volume, analysis time, and cost.

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

    SciTech Connect (OSTI)

    Not Available

    1988-11-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

    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.

  18. Separative power of an optimised concurrent gas centrifuge

    E-Print Network [OSTI]

    Bogovalov, S V

    2015-01-01T23:59:59.000Z

    The problem of separation of uranium isotopes in a concurrent gas centrifuge is solved analytically. Separative power of the optimized concurrent gas centrifuges equals to $\\delta U=12.7(V/700~{\\rm m/s})^2 (300 ~{\\rm K}/T)L, ~{\\rm kg ~SWU/yr}$, where $L$ and $V$ are the length and linear velocity of the rotor of the gas centrifuge, $T$ is the temperature. This formula well agrees with an empirical separative power of counter current gas centrifuges. The optimal value of the separative power is not unique on the plane $(p_w,v_z)$, where $p_w$ is pressure at the wall of the rotor and $v_z$ is axial velocity of the gas. This value is constant on a line defined by the equation $p_wv_z=constant$. Equations defining the mass flux and the electric power necessary to support the rotation of the gas centrifuge are obtained.

  19. Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong (Amy) [Amy; Phillips, Jon R.

    2012-07-01T23:59:59.000Z

    Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids producing a small plume containing uranium atoms. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement has high relative precision and detection limits approaching the femtogram range for uranium. It is independent of chemical form and degree of dilution with nuisance dust and other materials. High speed sample scanning and pinpoint characterization allow measurements on millions of particles/hour to detect and analyze the enrichment of trace uranium in samples. The spectrometer is assembled using commercially available components at comparatively low cost, and features a compact and low power design. Future designs can be engineered for reliable, autonomous deployment within an industrial plant environment. Two specific applications of the spectrometer are under development: 1) automated unattended aerosol sampling and analysis and 2) on-site small sample destructive assay measurement. The two applications propose game-changing technological advances in gaseous centrifuge enrichment plant (GCEP) safeguards verification. The aerosol measurement instrument, LAARS-environmental sampling (ES), collects aerosol particles from the plant environment in a purpose-built rotating drum impactor and then uses LAARS-ES to quickly scan the surface of the impactor to measure the enrichments of the captured particles. The current approach to plant misuse detection involves swipe sampling and offsite analysis. Though this approach is very robust it generally requires several months to obtain results from a given sample collection. The destructive assay instrument, LAARS-destructive assay (DA), uses a simple purpose-built fixture with a sampling planchet to collect adsorbed UF6 gas from a cylinder valve or from a process line tap or pigtail. A portable LAARS-DA instrument scans the microgram quantity of uranium collected on the planchet and the assay of the uranium is measured to ~0.15% relative precision. Currently, destructive assay samples for bias defect measurements are collected in small sample cylinders for offsite mass spectrometry measurement.

  20. An Inspector's Assessment of the New Model Safeguards Approach for Enrichment Plants

    SciTech Connect (OSTI)

    Curtis, Michael M.

    2007-07-31T23:59:59.000Z

    This conference paper assesses the changes that are being made to the Model Safeguards Approach for Gas Centrifuge Enrichment Plants.

  1. REMOVAL OF SOLIDS FROM HIGHLY ENRICHED URANIUM SOLUTIONS USING THE H-CANYON CENTRIFUGE

    SciTech Connect (OSTI)

    Rudisill, T; Fernando Fondeur, F

    2009-01-15T23:59:59.000Z

    Prior to the dissolution of Pu-containing materials in HB-Line, highly enriched uranium (HEU) solutions stored in Tanks 11.1 and 12.2 of H-Canyon must be transferred to provide storage space. The proposed plan is to centrifuge the solutions to remove solids which may present downstream criticality concerns or cause operational problems with the 1st Cycle solvent extraction due to the formation of stable emulsions. An evaluation of the efficiency of the H-Canyon centrifuge concluded that a sufficient amount (> 90%) of the solids in the Tank 11.1 and 12.2 solutions will be removed to prevent any problems. We based this conclusion on the particle size distribution of the solids isolated from samples of the solutions and the calculation of particle settling times in the centrifuge. The particle size distributions were calculated from images generated by scanning electron microscopy (SEM). The mean particle diameters for the distributions were 1-3 {micro}m. A significant fraction (30-50%) of the particles had diameters which were < 1 {micro}m; however, the mass of these solids is insignificant (< 1% of the total solids mass) when compared to particles with larger diameters. It is also probable that the number of submicron particles was overestimated by the software used to generate the particle distribution due to the morphology of the filter paper used to isolate the solids. The settling times calculated for the H-Canyon centrifuge showed that particles with diameters less than 1 to 0.5 {micro}m will not have sufficient time to settle. For this reason, we recommend the use of a gelatin strike to coagulate the submicron particles and facilitate their removal from the solution; although we have no experimental basis to estimate the level of improvement. Incomplete removal of particles with diameters < 1 {micro}m should not cause problems during purification of the HEU in the 1st Cycle solvent extraction. Particles with diameters > 1 {micro}m account for > 99% of the solid mass and will be efficiently removed by the centrifuge; therefore, the formation of emulsions during solvent extraction operations is not an issue. Under the current processing plan, the solutions from Tanks 11.1 and 12.2 will be transferred to the enriched uranium storage (EUS) tank following centrifugation. The solution from Tanks 11.1 and 12.2 may remain in the EUS tank for an extended time prior to purification. The effects of extended storage on the solution were not evaluated as part of this study.

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

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2010-08-11T23:59:59.000Z

    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.

  3. Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    Anheier, Norman C.; Cannon, Bret D.; Kulkarni, Gourihar R.; Munley, John T.; Nelson, Danny A.; Qiao, Hong (Amy) [Amy; Phillips, Jon R.

    2012-07-17T23:59:59.000Z

    Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids, producing a small atomic uranium vapor plume. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement is independent of chemical form and degree of dilution with nuisance dust and other materials. LAARS has high relative precision and detection limits approaching the femtogram range for U-235. The sample is scanned and assayed point-by-point at rates reaching 1 million measurements/hour, enabling LAARS to detect and analyze uranium in trace samples. The spectrometer is assembled using primarily commercially available components and features a compact design and automated analysis.Two specific gaseous centrifuge enrichment plant (GCEP) applications of the spectrometer are currently under development: 1) LAARS-Environmental Sampling (ES), which collects and analyzes aerosol particles for GCEP misuse detection and 2) LAARS-Destructive Assay (DA), which enables onsite enrichment DA sample collection and analysis for protracted diversion detection. The two applications propose game-changing technological advances in GCEP safeguards verification.

  4. Design of an Unattended Environmental Aerosol Sampling and Analysis System for Gaseous Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    Anheier, Norman C.; Munley, John T.; Alexander, M. L.

    2011-07-19T23:59:59.000Z

    The resources of the IAEA continue to be challenged by the rapid, worldwide expansion of nuclear energy production. Gaseous centrifuge enrichment plants (GCEPs) represent an especially formidable dilemma to the application of safeguard measures, as the size and enrichment capacity of GCEPs continue to escalate. During the early part of the 1990's, the IAEA began to lay the foundation to strengthen and make cost-effective its future safeguard regime. Measures under Part II of 'Programme 93+2' specifically sanctioned access to nuclear fuel production facilities and environmental sampling by IAEA inspectors. Today, the Additional Protocol grants inspection and environmental sample collection authority to IAEA inspectors at GCEPs during announced and low frequency unannounced (LFUA) inspections. During inspections, IAEA inspectors collect environmental swipe samples that are then shipped offsite to an analytical laboratory for enrichment assay. This approach has proven to be an effective deterrence to GCEP misuse, but this method has never achieved the timeliness of detection goals set forth by IAEA. Furthermore it is questionable whether the IAEA will have the resources to even maintain pace with the expansive production capacity of the modern GCEP, let alone improve the timeliness in reaching current safeguards conclusions. New safeguards propositions, outside of familiar mainstream safeguard measures, may therefore be required that counteract the changing landscape of nuclear energy fuel production. A new concept is proposed that offers rapid, cost effective GCEP misuse detection, without increasing LFUA inspection access or introducing intrusive access demands on GCEP operations. Our approach is based on continuous onsite aerosol collection and laser enrichment analysis. This approach mitigates many of the constraints imposed by the LFUA protocol, reduces the demand for onsite sample collection and offsite analysis, and overcomes current limitations associated with the in-facility misuse detection devices. Onsite environmental sample collection offers the ability to collect fleeting uranium hexafluoride emissions before they are lost to the ventilation system or before they disperse throughout the facility, to become deposited onto surfaces that are contaminated with background and historical production material. Onsite aerosol sample collection, combined with enrichment analysis, provides the unique ability to quickly detect stepwise enrichment level changes within the facility, leading to a significant strengthening of facility misuse deterence. We report in this paper our study of several GCEP environmental sample release scenarios and simulation results of a newly designed aerosol collection and particle capture system that is fully integrated with the Laser Ablation, Absorbance Ratio Spectrometry (LAARS) uranium particle enrichment analysis instrument that was developed at the Pacific Northwest National Laboratory.

  5. Analysis of gas centrifuge cascade for separation of multicomponent isotopes and optimal feed position

    SciTech Connect (OSTI)

    Chuntong Ying; Hongjiang Wu; Mingsheng Zhou; Yuguang Nie; Guangjun Liu [Tsinghua Univ., Beijing (China)

    1997-10-01T23:59:59.000Z

    Analysis of the concentration distribution in a gas centrifuge cascade for separation of multicomponent isotope mixtures is different from that in a cascade for separation of two-component mixtures. This paper presents the governing equations for a multicomponent isotope separation cascade. Numerically predicted separation factors for the gas centrifuge cascade agree well with the experimental data. A theoretical optimal feed position is derived for a short square cascade for a two-component mixture in a close-separation case. The optimal feed position for a gas centrifuge cascade for separation of multicomponent mixture is discussed.

  6. Lower Metal Enrichment of Virialized Gas in Minihalos

    E-Print Network [OSTI]

    Renyue Cen; Mario A. Riquelme

    2007-04-26T23:59:59.000Z

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

  7. Laser-based data acquisition in gas centrifuge environments using optical fibers

    SciTech Connect (OSTI)

    Cates, M. R.; Allison, S. W.; Marshall, B.; Davies, T. J.; Franks, L. A.; Nelson, M. A.; Noel, B. W.

    1984-08-24T23:59:59.000Z

    The operating environment of gas centrifuges poses three basic experimental problems: rotating reference frame, corrosive effects of UF/sub 6/ gas, and vacuum coupling. Diagnostic experiments in this environment effectively use fiber optics as laser transport systems and data extraction channels. Access to the interior of rotating centrifuges is only from a central nonrotating column assembly. Optical paths are often long and difficult to measure in static conditions with precision necessary in operating conditions. Residual traces of HF gas, from UF/sub 6/, damage exposed optical components over time. Diagnostic measurements requiring pulsed laser sources and analysis of fluorescence emissions, both from UF/sub 6/ gas and from temperature-sensitive phosphor are described, with emphasis on optical fiber components and experimental design configurations. The studies were done at Oak Ridge Gaseous Diffusion Plant through the Centrifuge Physics Department of the Centrifuge Division. The advantages of fiber optics methods include: optical path flexibility, small and adaptable size of components, utility in connection with moveable assemblies, and relative ease of vacuum isolation. 3 references, 6 figures.

  8. CFD Simulation of 3D Flow field in a Gas Centrifuge

    SciTech Connect (OSTI)

    Dongjun Jiang; Shi Zeng [Tsinghua University, Beijing, 100084 (China)

    2006-07-01T23:59:59.000Z

    A CFD method was used to study the whole flow field in a gas centrifuge. In this paper, the VSM (Vector Splitting Method) of the FVM (Finite Volume Method) was used to solve the 3D Navier-Stokes equations. An implicit second-order upwind scheme was adopted. The numerical simulation was successfully performed on a parallel cluster computer and a convergence result was obtained. The simulation shows that: in the withdrawal chamber, a strong detached shock wave is formed in front of the scoop; as the radial position increases, the shock becomes stronger and the distance to scoop front surface is smaller. An oblique shock forms in the clearance between the scoop and the centrifuge wall; behind the shock-wave, the radially-inward motion of gas is induced because of the imbalance of the pressure gradient and the centrifugal force. In the separation chamber, a countercurrent is introduced. This indicates that CFD method can be used to study the complex three-dimensional flow field of gas centrifuges. (authors)

  9. Stability analysis and testing of a train of centrifugal compressors for high pressure gas injection

    SciTech Connect (OSTI)

    Memmott, E.A. [Dresser-Rand Co., Olean, NY (United States)

    1999-07-01T23:59:59.000Z

    This paper describes the rotor dynamic stability analysis and the PTC-10 Class 1 test of a three body centrifugal compressor train for high pressure natural gas injection services. This train had a full load full pressure string test on hydrocarbon gases to a final discharge pressure of 500 BAR (7250 PSIA). Each compressor is of the back to back configuration, and is equipped with tilting pad seals, damper bearings, and a honeycomb labyrinth at the division wall with shunt holes. The driver is a gas turbine.

  10. From the Lab to the real world : sources of error in UF {sub 6} gas enrichment monitoring

    SciTech Connect (OSTI)

    Lombardi, Marcie L.

    2012-03-01T23:59:59.000Z

    Safeguarding uranium enrichment facilities is a serious concern for the International Atomic Energy Agency (IAEA). Safeguards methods have changed over the years, most recently switching to an improved safeguards model that calls for new technologies to help keep up with the increasing size and complexity of today’s gas centrifuge enrichment plants (GCEPs). One of the primary goals of the IAEA is to detect the production of uranium at levels greater than those an enrichment facility may have declared. In order to accomplish this goal, new enrichment monitors need to be as accurate as possible. This dissertation will look at the Advanced Enrichment Monitor (AEM), a new enrichment monitor designed at Los Alamos National Laboratory. Specifically explored are various factors that could potentially contribute to errors in a final enrichment determination delivered by the AEM. There are many factors that can cause errors in the determination of uranium hexafluoride (UF{sub 6}) gas enrichment, especially during the period when the enrichment is being measured in an operating GCEP. To measure enrichment using the AEM, a passive 186-keV (kiloelectronvolt) measurement is used to determine the {sup 235}U content in the gas, and a transmission measurement or a gas pressure reading is used to determine the total uranium content. A transmission spectrum is generated using an x-ray tube and a “notch” filter. In this dissertation, changes that could occur in the detection efficiency and the transmission errors that could result from variations in pipe-wall thickness will be explored. Additional factors that could contribute to errors in enrichment measurement will also be examined, including changes in the gas pressure, ambient and UF{sub 6} temperature, instrumental errors, and the effects of uranium deposits on the inside of the pipe walls will be considered. The sensitivity of the enrichment calculation to these various parameters will then be evaluated. Previously, UF{sub 6} gas enrichment monitors have required empty pipe measurements to accurately determine the pipe attenuation (the pipe attenuation is typically much larger than the attenuation in the gas). This dissertation reports on a method for determining the thickness of a pipe in a GCEP when obtaining an empty pipe measurement may not be feasible. This dissertation studies each of the components that may add to the final error in the enrichment measurement, and the factors that were taken into account to mitigate these issues are also detailed and tested. The use of an x-ray generator as a transmission source and the attending stability issues are addressed. Both analytical calculations and experimental measurements have been used. For completeness, some real-world analysis results from the URENCO Capenhurst enrichment plant have been included, where the final enrichment error has remained well below 1% for approximately two months.

  11. The effect of reformate gas enrichment on extinction limits and NOX formation

    E-Print Network [OSTI]

    Gülder, Ömer L.

    The effect of reformate gas enrichment on extinction limits and NOX formation in counterflow CH4 Dufferin Street, Toronto, Ont., Canada M3H 5T6 Abstract The reformate gas enriched counterflow lean premixed CH4/air flames were studied by numerical sim- ulation in this paper. The reformate gas was assumed

  12. ENRICHMENT OF THE DUST-TO-GAS MASS RATIO IN BONDI/JEANS ACCRETION/CLOUD SYSTEMS DUE TO UNEQUAL CHANGES IN DUST AND GAS INCOMING VELOCITIES

    E-Print Network [OSTI]

    Bellan, Paul M.

    ENRICHMENT OF THE DUST-TO-GAS MASS RATIO IN BONDI/JEANS ACCRETION/CLOUD SYSTEMS DUE TO UNEQUAL velocity profile from gas so that the dust-to-gas ratio is substantially enriched above the 1% interstellar of motion that the dust-to-gas ratio can become substantially enriched during Bondi- type accretion. Star

  13. A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge

    SciTech Connect (OSTI)

    de Stadler, M; Chand, K

    2007-11-12T23:59:59.000Z

    Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are presented.

  14. Aerodynamically induced radial forces in a centrifugal gas compressor: Part 2 -- Computational investigation

    SciTech Connect (OSTI)

    Flathers, M.B.; Bache, G.E.

    1999-10-01T23:59:59.000Z

    Radial loads and direction of a centrifugal gas compressor containing a high specific speed mixed flow impeller and a single tongue volute were determined both experimentally and computationally at both design and off-design conditions. The experimental methodology was developed in conjunction with a traditional ASME PTC-10 closed-loop test to determine radial load and direction. The experimental study is detailed in Part 1 of this paper (Moore and Flathers, 1998). The computational method employs a commercially available, fully three-dimensional viscous code to analyze the impeller and the volute interaction. An uncoupled scheme was initially used where the impeller and volute were analyzed as separate models using a common vaneless diffuser geometry. The two calculations were then repeated until the boundary conditions at a chosen location in the common vaneless diffuser were nearly the same. Subsequently, a coupled scheme was used where the entire stage geometry was analyzed in one calculation, thus eliminating the need for manual iteration of the two independent calculations. In addition to radial load and direction information, this computational procedure also provided aerodynamic stage performance. The effect of impeller front face and rear face cavities was also quantified. The paper will discuss computational procedures, including grid generation and boundary conditions, as well as comparisons of the various computational schemes to experiment. The results of this study will show the limitations and benefits of Computational Fluid Dynamics (CFD) for determination of radial load, direction, and aerodynamic stage performance.

  15. Measuring Deuterium Enrichment of Glucose Hydrogen Atoms by Gas Chromatography/Mass Spectrometry

    E-Print Network [OSTI]

    Antoniewicz, Maciek R.

    We developed a simple and accurate method for determining deuterium enrichment of glucose hydrogen atoms by electron impact gas chromatography mass spectrometry (GC/MS). First, we prepared 18 derivatives of glucose and ...

  16. A "Proof-of-Concept" Demonstration of RF-Based Technologies for UF6 Cylinder Tracking at Centrifuge Enrichment Plant

    SciTech Connect (OSTI)

    Pickett, Chris A [ORNL] [ORNL; Younkin, James R [ORNL] [ORNL; Kovacic, Donald N [ORNL] [ORNL; Dixon, E. T. [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Martinez, B. [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL)

    2007-01-01T23:59:59.000Z

    This effort describes how radio-frequency (RF) technology can be integrated into a uranium enrichment facility's nuclear materials accounting and control program to enhance uranium hexafluoride (UF6) cylinder tracking and thus provide benefits to both domestic and international safeguards. Approved industry-standard cylinders are used to handle and store UF6 feed, product, tails, and samples at uranium enrichment plants. In the international arena, the International Atomic Energy Agency (IAEA) relies on time-consuming manual cylinder inventory and tracking techniques to verify operator declarations and to detect potential diversion of UF6. Development of a reliable, automated, and tamper-resistant process for tracking and monitoring UF6 cylinders would greatly reduce the risk of false or misreported cylinder tare weights, diversion of nuclear material, concealment of excess production, utilization of undeclared cylinders, and misrepresentation of the cylinders contents. This paper will describe a "proof-of concept" system that was designed show the feasibility of using RF based technologies to track individual UF6 cylinders throughout their entire life cycle, and thus ensure both increased domestic accountability of materials and a more effective and efficient method for application of IAEA international safeguards at the site level. The proposed system incorporates RF-based identification devices, which provide a mechanism for a reliable, automated, and tamper-resistant tracking network. We explore how securely attached RF tags can be integrated with other safeguards technologies to better detect diversion of cylinders. The tracking system could also provide a foundation for integration of other types of safeguards that would further enhance detection of undeclared activities.

  17. Low temperature combustion using nitrogen enrichment to mitigate NOx from large bore natural gas fueled engines.

    SciTech Connect (OSTI)

    Biruduganti, M.; Gupta, S.; Sekar, R.; Energy Systems

    2010-01-01T23:59:59.000Z

    Low temperature combustion is identified as one of the pathways to meet the mandatory ultra low NO{sub x} emissions levels set by the regulatory agencies. Exhaust gas recirculation (EGR) is a well known technique to realize low NO{sub x} emissions. However, EGR has many built-in adverse ramifications that negate its advantages in the long term. This paper discusses nitrogen enrichment of intake air using air separation membranes as a better alternative to the mature EGR technique. This investigation was undertaken to determine the maximum acceptable level of nitrogen enrichment of air for a single-cylinder spark-ignited natural gas engine. NO{sub x} reduction as high as 70% was realized with a modest 2% nitrogen enrichment while maintaining power density and simultaneously improving fuel conversion efficiency (FCE). Any enrichment beyond this level degraded engine performance in terms of power density, FCE, and unburned hydrocarbon emissions. The effect of ignition timing was also studied with and without N{sub 2} enrichment. Finally, lean burn versus stoichiometric operation utilizing nitrogen enrichment was compared. Analysis showed that lean burn operation along with nitrogen enrichment is one of the effective pathways for realizing better FCE and lower NO{sub x} emissions.

  18. Cooling Limits on Galaxy Formation; Gas dynamical simulations incorporating a background UV field and metal enrichment

    E-Print Network [OSTI]

    John Hultman; Daniel Kaellander

    1997-11-12T23:59:59.000Z

    We present hydrodynamical simulations of the formation of galaxies in the mass range 10^9 - 10^13 solar masses, with the focus on the efficiency of gas cooling. The effect of a background UV radiation field, and the effect of metal enrichment of halo gas due to star formation and stellar evolution, are investigated. A background radiation field is found to strongly suppress the formation of galaxies with circular velocities less than approximately 50 km/s. The effect is, however, not large enough to reconcile hierarchical clustering models with observations. Metal enrichment of the halo gas increases the cooling rate at low redshifts. We find that the mass fraction of gas at virial temperatures may be reduced by a factor of two, in simulations with a UV background field added. The decrease in overall efficiency of gas cooling due to the inclusion of a UV background field can be more than compensated for by the increased cooling that follows metal enrichment of halo gas, but the effect may depend strongly on the assumed model of metal enrichment.

  19. New Prototype Safeguards Technology Offers Improved Confidence and Automation for Uranium Enrichment Facilities

    SciTech Connect (OSTI)

    Brim, Cornelia P.

    2013-03-04T23:59:59.000Z

    An important requirement for the international safeguards community is the ability to determine the enrichment level of uranium in gas centrifuge enrichment plants and nuclear fuel fabrication facilities. This is essential to ensure that countries with nuclear nonproliferation commitments, such as States Party to the Nuclear Nonproliferation Treaty, are adhering to their obligations. However, current technologies to verify the uranium enrichment level in gas centrifuge enrichment plants or nuclear fuel fabrication facilities are technically challenging and resource-intensive. NNSA’s Office of Nonproliferation and International Security (NIS) supports the development, testing, and evaluation of future systems that will strengthen and sustain U.S. safeguards and security capabilities—in this case, by automating the monitoring of uranium enrichment in the entire inventory of a fuel fabrication facility. One such system is HEVA—hybrid enrichment verification array. This prototype was developed to provide an automated, nondestructive assay verification technology for uranium hexafluoride (UF6) cylinders at enrichment plants.

  20. New Prototype Safeguards Technology Offers Improved Confidence and Automation for Uranium Enrichment Facilities

    SciTech Connect (OSTI)

    Brim, Cornelia P.

    2013-04-01T23:59:59.000Z

    An important requirement for the international safeguards community is the ability to determine the enrichment level of uranium in gas centrifuge enrichment plants and nuclear fuel fabrication facilities. This is essential to ensure that countries with nuclear nonproliferation commitments, such as States Party to the Nuclear Nonproliferation Treaty, are adhering to their obligations. However, current technologies to verify the uranium enrichment level in gas centrifuge enrichment plants or nuclear fuel fabrication facilities are technically challenging and resource-intensive. NNSA’s Office of Nonproliferation and International Security (NIS) supports the development, testing, and evaluation of future systems that will strengthen and sustain U.S. safeguards and security capabilities—in this case, by automating the monitoring of uranium enrichment in the entire inventory of a fuel fabrication facility. One such system is HEVA—hybrid enrichment verification array. This prototype was developed to provide an automated, nondestructive assay verification technology for uranium hexafluoride (UF6) cylinders at enrichment plants.

  1. Conceptual design for the field test and evaluation of the gas-phase UF/sub 6/ enrichment meter

    SciTech Connect (OSTI)

    Strittmatter, R.B.; Leavitt, J.N.; Slice, R.W.

    1980-12-01T23:59:59.000Z

    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. Data from proof-of-principle measurements using a laboratory prototype system are presented. A conceptual design for an enrichment monitor to be field tested and evaluated at the Oak Ridge Gaseous Diffusion Plant is reported.

  2. RESEARCH AND DEVELOPMENT OF AN INTEGRAL SEPARATOR FOR A CENTRIFUGAL GAS PROCESSING FACILITY

    SciTech Connect (OSTI)

    LANCE HAYS

    2007-02-27T23:59:59.000Z

    A COMPACT GAS PROCESSING DEVICE WAS INVESTIGATED TO INCREASE GAS PRODUCTION FROM REMOTE, PREVIOUSLY UN-ECONOMIC RESOURCES. THE UNIT WAS TESTED ON AIR AND WATER AND WITH NATURAL GAS AND LIQUID. RESULTS ARE REPORTED WITH RECOMMENDATIONS FOR FUTURE WORK.

  3. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    DOE Patents [OSTI]

    Biruduganti, Munidhar S. (Naperville, IL); Gupta, Sreenath Borra (Naperville, IL); Sekar, R. Raj (Naperville, IL); McConnell, Steven S. (Shorewood, IL)

    2008-11-25T23:59:59.000Z

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  4. EIS-0471: Department of Energy Loan Guarantee to Support Proposed Eagle Rock Enrichment Facility in Bonneville County, Idaho

    Broader source: Energy.gov [DOE]

    This EIS evaluates the environmental impacts of construction, operation, and decommissioning of the proposed Eagle Rock Enrichment Facility (EREF), a gas centrifuge uranium enrichment facility to be located in a rural area in western Bonneville County, Idaho. (DOE adopted this EIS issued by NRC on 04/13/2007.)

  5. The production characteristics of a solution gas-drive reservoir as measured on a centrifugal model

    E-Print Network [OSTI]

    Goodwin, Robert Jennings

    1955-01-01T23:59:59.000Z

    Mixtures and Cetus Oil - Natural Gas Mixtures Reservoir Pez&ormance Characteristics for Test Number 17 Through Well Number Three with Fluid Number One Reservoir Perfozmanco Characteristics for Test Number 32 Through Well Number One with Fluid Number... data to show that recovery 8?9, . 10 is a function of well spacing for the soluti on gas drive producing mecha- 12 nism while Kaveler has countered the proposition with other data. Tomlinson and Craze and 77uckley have interprei, ed the same API 11...

  6. Gas distribution, metal enrichment, and baryon fraction in Gaussian and non-Gaussian universes

    E-Print Network [OSTI]

    Umberto Maio

    2011-12-12T23:59:59.000Z

    We study the cosmological evolution of baryons in universes with and without primordial non-Gaussianities via (large scale) N-body/hydrodynamical simulations, including gas cooling, star formation, stellar evolution, chemical enrichment from both population III and population II regimes, and feedback effects. We find that large fnl values for non-Gaussianities can alter the gas probability distribution functions, the metal pollution history, the halo baryon, gas and stellar fractions, mostly at early times. More precisely: (i) non-Gaussianities lead to an earlier evolution of primordial gas, structures, and star formation; (ii) metal enrichment starts earlier (with respect to the Gaussian scenario) in non-Gaussian models with larger fnl; (iii) gas fractions within the haloes are not significantly affected by the different values of fnl, with deviations of ~1-10%; (iv) the stellar fraction is quite sensitive to non-Gaussianities at early times, with discrepancies reaching up to a factor of ~10 at very high z, and rapidly converging at low z; (v) the trends at low redshift are independent from fnl: they are mostly led by the ongoing baryonic evolution and by the feedback mechanisms, which determine a ~25%-30% discrepancy in the baryon fraction of galaxy groups/clusters with respect to the cosmic values; (vi) non-Gaussianity impacts on the cluster X-ray emission or on the SZ effect(s) are expected to be not very large and dominated by feedback mechanisms, whereas some effects on the 21-cm emission can be expected at early times; (vii) in order to address non-Gaussianities in the cosmological structure contest, high-redshift (z~10) investigations are required: first stars, galaxies, quasars, and GRBs may be potential cosmological probes of non-Gaussianities.

  7. Stable Isotope Enrichment Capabilities at ORNL

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

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

  8. Nuclear non-proliferation regime effectiveness : an integrated methodology for analyzing highly enriched uranium production scenarios at gas centrifuge enrichment plants

    E-Print Network [OSTI]

    Kwak, Taeshin (Taeshin S.)

    2010-01-01T23:59:59.000Z

    The dramatic change in the international security environment after the collapse of the bipolar system has had a negative impact on the effectiveness of the existing nuclear non-proliferation regime. Furthermore, the success ...

  9. Keeping Environmental Enrichment Enriching

    E-Print Network [OSTI]

    Kuczaj, Stan; Lacinak, Thad; Fad, Otto; Trone, Marie; Solangi, Moby; Ramos, Joana

    2002-01-01T23:59:59.000Z

    nature: Environmental enrichment for captive animals (pp.nature: Environmental enrichment for captive animals (pp.G. (1999). Environmental enrichment for laboratory rodents:

  10. Centrifugal pyrocontactor

    DOE Patents [OSTI]

    Chow, L.S.; Leonard, R.A.

    1993-10-19T23:59:59.000Z

    A method is described for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor. 6 figures.

  11. Centrifugal pyrocontactor

    DOE Patents [OSTI]

    Chow, Lorac S. (Willowbrook, IL); Leonard, Ralph A. (River Forest, IL)

    1993-01-01T23:59:59.000Z

    A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

  12. Batch methods for enriching trace impurities in hydrogen gas for their further analysis

    DOE Patents [OSTI]

    Ahmed, Shabbir; Lee, Sheldon H.D.; Kumar, Romesh; Papdias, Dionissios D.

    2014-07-15T23:59:59.000Z

    Provided herein are batch methods and devices for enriching trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentrating impurities using hydrogen transport membranes wherein the time period for concentrating the sample is calculated on the basis of optimized membrane characteristics, comprising its thickness and permeance, with optimization of temperature, and wherein the enrichment of trace impurities is proportional to the pressure ratio P.sub.hi/P.sub.lo and the volume ratio V.sub.1/V.sub.2, with following detection of the impurities using commonly-available detection methods.

  13. LARGE EDDY SIMULATION/EULERIAN PROBABILITY DENSITY FUNCTION APPROACH FOR SIMULATING HYDROGEN-ENRICHED GAS TURBINE

    E-Print Network [OSTI]

    Raman, Venkat

    while the small-scale motions are modeled using sub-filter models. Since gas-turbine relevant combustion providing better input for the combustion models. Developing LES-based combustion models for stationary gas) based approach is used here to deal with the complexities of gas turbine combustion. In the PDF approach

  14. Water alternating enriched gas injection to enhance oil production and recovery from San Francisco Field, Colombia 

    E-Print Network [OSTI]

    Rueda Silva, Carlos Fernando

    2003-01-01T23:59:59.000Z

    The main objectives of this study are to determine the most suitable type of gas for a water-alternating-gas (WAG) injection scheme, the WAG cycle time, and gas injection rate to increase oil production rate and recovery from the San Francisco field...

  15. Water alternating enriched gas injection to enhance oil production and recovery from San Francisco Field, Colombia

    E-Print Network [OSTI]

    Rueda Silva, Carlos Fernando

    2003-01-01T23:59:59.000Z

    The main objectives of this study are to determine the most suitable type of gas for a water-alternating-gas (WAG) injection scheme, the WAG cycle time, and gas injection rate to increase oil production rate and recovery from the San Francisco field...

  16. Spontaneous Enrichment of Organic Molecules from Aqueous and Gas Phases into a Stable Metallogel

    E-Print Network [OSTI]

    Xing, Bengang

    -concentration hazardous organics, for example, chlorobenzene or toluene in water or poly- aromatic hydrocarbons (PAHs or gas phases. Using nonpolar solvents to extract organic hazards from water is hardly practical since

  17. ON THE POSSIBILITY OF ENRICHMENT AND DIFFERENTIATION IN GAS GIANTS DURING BIRTH BY DISK INSTABILITY

    SciTech Connect (OSTI)

    Boley, Aaron C. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Durisen, Richard H., E-mail: aaron.boley@gmail.co [Department of Astronomy, Indiana University, 727 East 3rd Street, Swain West 319, Bloomington, IN 47405 (United States)

    2010-11-20T23:59:59.000Z

    We investigate the coupling between rock-size solids and gas during the formation of gas giant planets by disk fragmentation in the outer regions of massive disks. In this study, we use three-dimensional radiative hydrodynamic simulations and model solids as a spatial distribution of particles. We assume that half of the total solid fraction is in small grains and half in large solids. The former are perfectly entrained with the gas and set the opacity in the disk, while the latter are allowed to respond to gas drag forces, with the back reaction on the gas taken into account. To explore the maximum effects of gas-solid interactions, we first consider 10 cm size particles. We then compare these results to a simulation with 1 km size particles, which explores the low-drag regime. We show that (1) disk instability planets have the potential to form large cores due to aerodynamic capturing of rock-size solids in spiral arms before fragmentation; (2) temporary clumps can concentrate tens of M{sub +} of solids in very localized regions before clump disruption; (3) the formation of permanent clumps, even in the outer disk, is dependent on the grain-size distribution, i.e., the opacity; (4) nonaxisymmetric structure in the disk can create disk regions that have a solids-to-gas ratio greater than unity; (5) the solid distribution may affect the fragmentation process; (6) proto-gas giants and proto-brown dwarfs can start as differentiated objects prior to the H{sub 2} collapse phase; (7) spiral arms in a gravitationally unstable disk are able to stop the inward drift of rock-size solids, even redistributing them to larger radii; and (8) large solids can form spiral arms that are offset from the gaseous spiral arms. We conclude that planet embryo formation can be strongly affected by the growth of solids during the earliest stages of disk accretion.

  18. Experimental studies of steam-propane and enriched gas injection for the Minas light crude oil 

    E-Print Network [OSTI]

    Yudishtira, Wan Dedi

    2003-01-01T23:59:59.000Z

    Experimental studies were carried out to compare the benefits of propane as an additive in steam injection and in lean gas injection to enhance production for the Minas light crude oil (34?API). The studies on steam-propane were specifically...

  19. Experimental studies of steam-propane and enriched gas injection for the Minas light crude oil

    E-Print Network [OSTI]

    Yudishtira, Wan Dedi

    2003-01-01T23:59:59.000Z

    Experimental studies were carried out to compare the benefits of propane as an additive in steam injection and in lean gas injection to enhance production for the Minas light crude oil (34?API). The studies on steam-propane were specifically...

  20. Laser Isotope Enrichment for Medical and Industrial Applications

    SciTech Connect (OSTI)

    Leonard Bond

    2006-07-01T23:59:59.000Z

    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".

  1. The PHRI Geotechnical Centrifuge [abstract

    E-Print Network [OSTI]

    Terashi, M; Kitazume, M.; Tanaka, H.

    1984-01-01T23:59:59.000Z

    Total weight of the centrifuge (t) 1600xl600 I ·t t FIGURECur. it · mml PHRI Geotechnical Centrifuge I I I I I I I I IADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium on

  2. The origin of the double main sequence in Omega Centauri: Helium enrichment due to gas fueling from its ancient host galaxy ?

    E-Print Network [OSTI]

    Kenji Bekki; John E. Norris

    2005-12-15T23:59:59.000Z

    Recent observational studies of $\\omega$ Centauri by {\\it Hubble Space Telescope} have discovered a double main sequence in the color magnitude diagrams (CMDs) of its stellar populations. The stellar population with the blue main sequence (bMS) is observationally suggested to have a helium abundance much larger, by $\\Delta Y\\sim 0.12$, than that of the red main sequence (rMS). By using somewhat idealized models in which stars of the bMS are formed from gas ejected from those of the rMS, we quantitatively investigate whether the helium overabundance of the bMS can result from self-enrichment from massive AGB stars, from mass loss of very massive young stars, or from type II supernovae within $\\omega$ Cen. We show that as long as the helium enrichment is due to ejecta from the rMS formed earlier than the bMS, none of the above three enrichment scenarios can explain the observed properties of the bMS self-consistently for reasonable IMFs. The common, serious problem in all cases is that the observed number fraction of the bMS can not be explained without assuming unusually top-heavy IMFs. This failure of the self-enrichment scenarios implies that most of the helium-enriched gas necessary for the formation of the bMS originated from other external sources. We thus suggest a new scenario that most of the second generation of stars (i.e., the bMS) in $\\omega$ Cen could be formed from gas ejected from field stellar populations that surrounded $\\omega$ Cen when it was a nucleus of an ancient dwarf galaxy.

  3. Metal enrichment processes

    E-Print Network [OSTI]

    S. Schindler; A. Diaferio

    2008-01-07T23:59:59.000Z

    There are many processes that can transport gas from the galaxies to their environment and enrich the environment in this way with metals. These metal enrichment processes have a large influence on the evolution of both the galaxies and their environment. Various processes can contribute to the gas transfer: ram-pressure stripping, galactic winds, AGN outflows, galaxy-galaxy interactions and others. We review their observational evidence, corresponding simulations, their efficiencies, and their time scales as far as they are known to date. It seems that all processes can contribute to the enrichment. There is not a single process that always dominates the enrichment, because the efficiencies of the processes vary strongly with galaxy and environmental properties.

  4. Energy Savings for Centrifugal Compressors

    E-Print Network [OSTI]

    Fisher, D.

    2011-01-01T23:59:59.000Z

    Current design improvements of both the rotating and stationary aerodynamic components of centrifugal compressors can greatly increase the efficiency of vintage machines. A centrifugal compressor built in the 1970's or 1980's might have an external...

  5. Centrifugally decoupling touchdown bearings

    DOE Patents [OSTI]

    Post, Richard F

    2014-06-24T23:59:59.000Z

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  6. Centrifugal unbalance detection system

    DOE Patents [OSTI]

    Cordaro, Joseph V. (Martinez, GA); Reeves, George (Graniteville, SC); Mets, Michael (Aiken, SC)

    2002-01-01T23:59:59.000Z

    A system consisting of an accelerometer sensor attached to a centrifuge enclosure for sensing vibrations and outputting a signal in the form of a sine wave with an amplitude and frequency that is passed through a pre-amp to convert it to a voltage signal, a low pass filter for removing extraneous noise, an A/D converter and a processor and algorithm for operating on the signal, whereby the algorithm interprets the amplitude and frequency associated with the signal and once an amplitude threshold has been exceeded the algorithm begins to count cycles during a predetermined time period and if a given number of complete cycles exceeds the frequency threshold during the predetermined time period, the system shuts down the centrifuge.

  7. AMERICAN LITERATUREON GEOTECHNICAL CENTRIFUGE MODELING 1931 - 1984

    E-Print Network [OSTI]

    Cheney, J.A.

    1984-01-01T23:59:59.000Z

    Loading During Dynamic Centrifuge Tests," S . ~. Thesis,S. Bang and J.F. Mitchell, "Centrifuge Modeling of a LateralJ.A. Cheney, "Drum Centrifuge Studies of Overconsolidated

  8. CENTRIFUGE PREDICTION OF EGRESS SYSTEM PERFORMANCE

    E-Print Network [OSTI]

    Schmidt, R.M.; Funston, N.E.; Webbeking, V.T.; Housen, K.R.; Holsapple, K.A.; Voss, M.E.

    1984-01-01T23:59:59.000Z

    ~ ctuator hit ltd (sec) CENTRIFUGE I I F IG URL PREDICTIONStudy, Test No. HV12-T1C, Centrifuge Model Test Frogram."ADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium on

  9. Centrifugal shot blast system

    SciTech Connect (OSTI)

    NONE

    1998-02-01T23:59:59.000Z

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997.

  10. Centrifuge treatment of coal tar

    SciTech Connect (OSTI)

    L.A. Kazak; V.Z. Kaidalov; L.F. Syrova; O.S. Miroshnichenko; A.S. Minakov [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

    2009-07-15T23:59:59.000Z

    New technology is required for the removal of water and heavy fractions from regular coal tar. Centrifuges offer the best option. Purification of coal tar by means of centrifuges at OAO NLMK permits the production of pitch coke or electrode pitch that complies with current standards.

  11. Direct formation of supermassive black holes in metal-enriched gas at the heart of high-redshift galaxy mergers

    E-Print Network [OSTI]

    Mayer, Lucio; Bonoli, Silvia; Quinn, Thomas; Roskar, Rok; Shen, Sijing; Wadsley, James

    2014-01-01T23:59:59.000Z

    We present novel 3D multi-scale SPH simulations of gas-rich galaxy mergers between the most massive galaxies at $z \\sim 8 - 10$, designed to scrutinize the direct collapse formation scenario for massive black hole seeds proposed in \\citet{mayer+10}. The simulations achieve a resolution of 0.1 pc, and include both metallicity-dependent optically-thin cooling and a model for thermal balance at high optical depth. We consider different formulations of the SPH hydrodynamical equations, including thermal and metal diffusion. When the two merging galaxy cores collide, gas infall produces a compact, optically thick nuclear disk with densities exceeding $10^{-10}$ g cm$^3$. The disk rapidly accretes higher angular momentum gas from its surroundings reaching $\\sim 5$ pc and a mass of $\\gtrsim 10^9$ $M_{\\odot}$ in only a few $10^4$ yr. Outside $\\gtrsim 2$ pc it fragments into massive clumps. Instead, supersonic turbulence prevents fragmentation in the inner parsec region, which remains warm ($\\sim 3000-6000$ K) and dev...

  12. A Robust and Flexible Design for GCEP Unattended Online Enrichment Monitoring: An OLEM Collection Node Network

    SciTech Connect (OSTI)

    Younkin, James R [ORNL] [ORNL; March-Leuba, Jose A [ORNL] [ORNL; Garner, James R [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    Oak Ridge National Laoratory (ORNL) has engineered an on-line enrichment monitor (OLEM) to continuously measure U-235 emissions from the UF6 gas flowing through a unit header pipe of a gas centrifuge enrichment plant (GCEP) as a component of the International Atomic Energy Agency s (IAEA) new generation of technology to support enrichment plant safeguards1. In contrast to other enrichment monitoring approaches, OLEM calibrates and corrects for the pressure and temperature dependent UF6 gas-density without external radiation sources by using the inherent unit header pipe pressure dynamics and combining U-235 gamma-ray spectrometery using a shielded NaI detector with gas pressure and temperature data near the spectrum measurement point to obtain the enrichment of the gas as a function of time. From a safeguards perspective, OLEM can provide early detection of a GCEP being misused for production of highly enriched uranium, but would not detect directly the isolation and use of a cascade within the production unit to produce HEU. OLEM may also reduce the number of samples collected for destructive assay and, if coupled with load cell monitoring, could support isotope mass balance verification and unattended cylinder verification. The earlier paper presented OLEM as one component along with shared load cells and unattended cylinder verification, in the IAEA emering toolbox for unattended instruments at GCEPs1 and described the OLEM concept and how previous modeling studies and field measurements helped confirm the viability of a passive on-line enrichment monitor for meeting IAEA objectives and to support the development of performance targets. Phase I of the United States Support Program (USSP) OLEM project completed a preliminary hardware, software and communications design; phase II will build and test field prototypes in controlled laboratory settings and then at an operational facility. That paper also discussed many of the OLEM collection node commercial off the shelf (COTS) components and summarized the OLEM collection node data security provisions. This paper will discuss a secure and redundant network of OLEM collection nodes, auxiliary detection units and supporting junction boxes distributed throughout a facility for monitoring enrichment on product, feed and tails unit header pipes; the purpose and capability of the built-in Electronic Optical Sealing System (EOSS) network gateway; and a network approach for obtaining reliable and authenticated pressure measurements.

  13. Microwave assisted centrifuge and related methods

    DOE Patents [OSTI]

    Meikrantz, David H. (Idaho Falls, ID) [Idaho Falls, ID

    2010-08-17T23:59:59.000Z

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  14. Centrifugal dryers keep pace with the market

    SciTech Connect (OSTI)

    Fiscor, S.

    2008-03-15T23:59:59.000Z

    New plant design and upgrades create a shift in dewatering strategies. The article describes recent developments. Three major manufacturers supply centrifugal dryers - TEMA, Centrifugal & Mechanical Industries (CMI) and Ludowici. CMI introduced a line of vertical centrifugal dryers. TEMA improved the techniques by developing a horizontal vibratory centrifuge (HVC) which simplified maintenance. 3 figs., 1 photo.

  15. Improving accuracy and reliability of 186-keV measurements for unattended enrichment monitoring

    SciTech Connect (OSTI)

    Ianakiev, Kiril D [Los Alamos National Laboratory; Boyer, Brian D [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Moss, Calvin E [Los Alamos National Laboratory; Goda, Joetta M [Los Alamos National Laboratory; Favalli, Andrea [Los Alamos National Laboratory; Lombardi, Marcie [Los Alamos National Laboratory; Paffett, Mark T [Los Alamos National Laboratory; Hill, Thomas R [Los Alamos National Laboratory; MacArthur, Duncan W [Los Alamos National Laboratory; Smith, Morag K [Los Alamos National Laboratory

    2010-04-13T23:59:59.000Z

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants (GCEPs), whilst reducing the inspection effort, is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One aspect of this measurement is a simple, reliable and precise passive measurement of the 186-keV line from {sup 235}U. (The other information required is the amount of gas in the pipe. This can be obtained by transmission measurements or pressure measurements). In this paper we describe our research efforts towards such a passive measurement system. The system includes redundant measurements of the 186-keV line from the gas and separately from the wall deposits. The design also includes measures to reduce the effect of the potentially important background. Such an approach would practically eliminate false alarms and can maintain the operation of the system even with a hardware malfunction in one of the channels. The work involves Monte Carlo modeling and the construction of a proof-of-principle prototype. We will carry out experimental tests with UF{sub 6} gas in pipes with and without deposits in order to demonstrate the deposit correction.

  16. Mathematical modeling of mass transfer during centrifugal filtration of polydisperse suspensions

    SciTech Connect (OSTI)

    V.F. Pozhidaev; Y.B. Rubinshtein; G.Y. Golberg; S.A. Osadchii [Dahl East Ukraine National University, Lugansk (Ukraine)

    2009-07-15T23:59:59.000Z

    A mass-transfer equation, the solution of which for given boundary conditions makes it possible to derive in analytical form a relationship between the extraction of the solid phase of a suspension into the centrifuge effluent and the fineness of the particles, is suggested on the basis of a model; this is of particular importance in connection with the development of a new trend in the utilization of filtering centrifuges - concentration of coal slurries by extraction into the centrifuge effluent of the finest particles, the ash content of which is substantially higher than that of particles of the coarser classes. Results are presented for production studies under conditions at an active establishment (the Neryungrinskaya Enrichment Factory); these results confirmed the adequacy of the mathematical model proposed: convergence of computed and experimental data was within the limits of the experimental error (no more than 3%). The model in question can be used to predict results of suspension separation by centrifugal filtration.

  17. RELATIONSHIPS FOR MODELLING WATER FLOW IN GEOTECHNICAL CENTRIFUGE MODELS [abstract

    E-Print Network [OSTI]

    Goodings, Deborah

    1984-01-01T23:59:59.000Z

    relationships between centrifuge model and prototype waterADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held on

  18. The centrifuge as an aid to the designer

    E-Print Network [OSTI]

    Craig, William H

    1984-01-01T23:59:59.000Z

    on Application of Centrifuge Modelling to GeotechnicalOperation of a geotechnical centrifuge from 1970 to 1979.ADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium on

  19. A Centrifuge Modeling Procedure for Landfill Cover Subsidence

    E-Print Network [OSTI]

    Sterling, Harry J; Ronayne, Michael C

    1984-01-01T23:59:59.000Z

    Advances in Geotechncial Centrifuge Modeling, University ofADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held on

  20. Tests on piles installed in flight on the centrifuge

    E-Print Network [OSTI]

    Allard, M.A.

    1984-01-01T23:59:59.000Z

    ADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held onl I I I Committee on Centrifuges of the International

  1. The Enriched Xenon Observatory

    SciTech Connect (OSTI)

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

    2009-12-17T23:59:59.000Z

    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.

  2. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect (OSTI)

    William A. Greene; Patricia A. Kirk; Richard Hayes; Joshua Riley

    2005-10-28T23:59:59.000Z

    SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, has engineered and developed a system for use within the U.S. Department of Energy (DOE) Environmental Management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. SpinTek II High Shear Rotary Membrane Filtration System is a unique compact crossflow membrane system that has large, demonstrable advantages in performance and cost compared to currently available systems: (1) High fluid shear prevents membrane fouling even with very high solids content; hazardous and radioactive components can be concentrated to the consistency of a pasty slurry without fouling. (2) Induced turbulence and shear across the membrane increases membrane flux by a factor of ten over existing systems and allows operation on fluids not otherwise treatable. (3) Innovative ceramic membrane and mechanical sealing technology eliminates compatibility problems with aggressive DOE waste streams. (4) System design allows rapid, simple disassembly for inspection or complete decontamination. (5) Produces colloidal- and suspended-solids-free filtrate without the addition of chemicals. The first phase of this project (PRDA maturity stage 5) completed the physical scale-up of the SpinTek unit and verified successful scale-up with surrogate materials. Given successful scale-up and DOE concurrence, the second phase of this project (PRDA maturity stage 6) will provide for the installation and operation of the full-scale two-stage SpinTek unit for treatment of a DOE waste-stream at the Los Alamos National Laboratory. This technology has very broad application across the DOE system. Nineteen DOE technical needs areas (Appendix C) have been identified. Following successful full-scale demonstration for treatment of DOE wastes, this innovative technology will be rapidly deployed on a wide range of waste and process streams throughout the DOE system.

  3. The L.C.P.C. Centrifuge

    E-Print Network [OSTI]

    Corte, J.F.

    1984-01-01T23:59:59.000Z

    LABORATORY Figure 6. L.C.P.C. centrifuge facilities I I I In e r a l v i e w of t h e centrifuge a nd i ts d r i ve u nit . f l r g CENTRIFUGE CHAMBER l f MOTOR PIT 1. AC MOTOR -

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

    SciTech Connect (OSTI)

    Not Available

    1994-01-01T23:59:59.000Z

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

  5. Centrifugal separator devices, systems and related methods

    DOE Patents [OSTI]

    Meikrantz, David H. (Idaho Falls, ID); Law, Jack D. (Pocatello, ID); Garn, Troy G. (Idaho Falls, ID); Todd, Terry A. (Aberdeen, ID); Macaluso, Lawrence L. (Carson City, NV)

    2012-03-20T23:59:59.000Z

    Centrifugal separator devices, systems and related methods are described. More particularly, fluid transfer connections for a centrifugal separator system having support assemblies with a movable member coupled to a connection tube and coupled to a fixed member, such that the movable member is constrained to movement along a fixed path relative to the fixed member are described. Also, centrifugal separator systems including such fluid transfer connections are described. Additionally, methods of installing, removing and/or replacing centrifugal separators from centrifugal separator systems are described.

  6. Motility fractionation of bacteria by centrifugation

    E-Print Network [OSTI]

    Claudio Maggi; Alessia Lepore; Jacopo Solari; Alessandro Rizzo; Roberto Di Leonardo

    2013-10-10T23:59:59.000Z

    Centrifugation is a widespread laboratory technique used to separate mixtures into fractions characterized by a specific size, weight or density. We demonstrate that centrifugation can be also used to separate swimming cells having different motility. To do this we study self-propelled bacteria under the influence of an external centrifugal field. Using dynamic image correlation spectroscopy we measure the spatially resolved motility of bacteria after centrifugation. A significant gradient in swimming-speeds is observed for increasing centrifugal speeds. Our results can be reproduced by a model that treats bacteria as "hot" colloidal particles having a diffusion coefficient that depends on the swimming speed.

  7. Centrifugal force in Kerr geometry

    E-Print Network [OSTI]

    Sai Iyer; A R Prasanna

    1992-07-31T23:59:59.000Z

    We have obtained the correct expression for the centrifugal force acting on a particle at the equatorial circumference of a rotating body in the locally non-rotating frame of the Kerr geometry. Using this expression for the equilibrium of an element on the surface of a slowly rotating Maclaurin spheroid, we obtain the expression for the ellipticity (as discussed earlier by Abramowicz and Miller) and determine the radius at which the ellipticity is maximum.

  8. Ethane enrichment and propane depletion in subsurface gases indicate gas hydrate occurrence in marine sediments at southern Hydrate Ridge offshore Oregon

    SciTech Connect (OSTI)

    Milkov, Alexei V.; Claypool, G E.; Lee, Young-Joo; Torres, Marta E.; Borowski, W S.; Tomaru, H; Sassen, Roger; Long, Philip E.

    2004-07-02T23:59:59.000Z

    The recognition of finely disseminated gas hydrate in deep marine sediments heavily depends on various indirect techniques because this mineral quickly decomposes upon recovery from in situ pressure and temperature conditions. Here, we discuss molecular properties of closely spaced gas voids (formed as a result of core recovery) and gas hydrates from an area of relatively low gas flux at the flanks of the southern Hydrate Ridge Offshore Oregon (ODP Sites 1244, 1245 and 1247).

  9. NEBULAR FORMATION OF FAYALITIC OLIVINE: INEFFECTIVENESS OF DUST ENRICHMENT. A. V. Fedkin1

    E-Print Network [OSTI]

    Grossman, Lawrence

    NEBULAR FORMATION OF FAYALITIC OLIVINE: INEFFECTIVENESS OF DUST ENRICHMENT. A. V. Fedkin1 and L temperature, and thus in a nebular region more oxidized than solar gas, pre- sumably due to enrichment in dust of regions enriched in dust relative to its complementary gas yields systems more oxidizing than a solar gas

  10. Centrifugal quantum states of neutrons

    E-Print Network [OSTI]

    V. V. Nesvizhevsky; A. K. Petukhov; K. V. Protasov; A. Yu. Voronin

    2008-06-24T23:59:59.000Z

    We propose a method for observation of the quasi-stationary states of neutrons, localized near the curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi-potential. This phenomenon is an example of an exactly solvable "quantum bouncer" problem that could be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop formalism, which describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.

  11. ANALYTICAL AND CENTRIFUGE STUDIES LATERALLY LOADED SINGLE PILES

    E-Print Network [OSTI]

    Chandrasekaran, V.S.; Kulkarni, K.R.; King, G.J.W.

    1984-01-01T23:59:59.000Z

    the Ap p licati on of Centrifuge Modelling to GeotechnicalKing, G.J.W. (1984). Centrifuge tests on laterally loadedgeotec h nical centrifuge operations. Geotechnique (30), 3,

  12. DYNAMIC BEHAVIOR OF FOUNDATIONS: AN EXPERIMENTAL STUDY IN A CENTRIFUGE

    E-Print Network [OSTI]

    Hushman, B.

    1984-01-01T23:59:59.000Z

    1975. Sco tt, R. F . , "Centrifuge Studies of Cyclic LateDynam i c Pile Tests by Centrifuge Mo deling ," Proc. 6th WoADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium on

  13. Centrifuge modelling of artificial sand islands in earthquakes

    E-Print Network [OSTI]

    Lee, F.H.; Schofield, A.N.

    1984-01-01T23:59:59.000Z

    el d, A.N. ( 1983 ) . Two Centrifuge Hode : Tes t s: o:-: S~Partial Liquefaction in a Centrifuge Model Embankment in anand Earthquake Geotechnical Centrifuge Modelling, Proc. Int,

  14. Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

    DOE Patents [OSTI]

    Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.

    2014-08-26T23:59:59.000Z

    An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

  15. Centrifugal deformations of the gravitational kink

    E-Print Network [OSTI]

    Paolo Maraner; Jiannis K. Pachos

    2008-11-29T23:59:59.000Z

    The Kaluza-Klein reduction of 4d conformally flat spacetimes is reconsidered. The corresponding 3d equations are shown to be equivalent to 2d gravitational kink equations augmented by a centrifugal term. For space-like gauge fields and non-trivial values of the centrifugal term the gravitational kink solutions describe a spacetime that is divided in two disconnected regions.

  16. Apparatus for centrifugal separation of coal particles

    DOE Patents [OSTI]

    Dickie, William (New Eagle, PA); Cavallaro, Joseph A. (Mt. Keesport, PA); Killmeyer, Richard P. (Pleasant Hills, PA)

    1991-01-01T23:59:59.000Z

    A gravimetric cell for centrifugal separation of fine coal by density has a cylindrical body and a butterfly valve or other apparatus for selectively sealing the body radially across the approximate center of the cylinder. A removable top is provided which seals the cylinder in the centrifuge and in unvented areas.

  17. annular centrifugal contactor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and increased engine downsizing in the automotive industry are pushing the turbocharger centrifugal (more) Kapoor, P. 2014-01-01 83 Transition to Centrifugal Particle...

  18. annular centrifugal contactors: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and increased engine downsizing in the automotive industry are pushing the turbocharger centrifugal (more) Kapoor, P. 2014-01-01 83 Transition to Centrifugal Particle...

  19. The plasma centrifuge: A compact, low cost, stable isotope separator. Phase 2 final technical report, September 15, 1991--September 14, 1995

    SciTech Connect (OSTI)

    Guss, W.

    1996-09-05T23:59:59.000Z

    Enriched stable isotopes are required for production of radionuclides as well as for research and diagnostic uses. Science Research Laboratory (SRL) has developed a plasma centrifuge for moderate throughput of enriched stable isotopes, such as {sup 13}C, {sup 17}O, {sup 18}O, and {sup 203}Tl, for medical as well as other applications. Dwindling isotope stocks have restricted the use of enriched isotopes and their associated labeled organic molecules in medical imaging to very few research facilities because of high costs of isotope separation. With the introduction of the plasma centrifuge separator, the cost per separated gram of even rarely occurring isotopes ({le} 1% natural abundance) is potentially many times lower than with other separation technologies (cryogenic distillation and calutrons). The centrifuge is a simple, robust, pulsed electrical discharge device that has successfully demonstrated isotope separation of small (mg) quantities of {sup 26}Mg. Based on the results of the Phase 2 program, modest enhancements to the power supplies and cooling systems, a centrifuge separator will have high repetition rate (60 pps) and high duty cycle (60%) to produce in one month kilogram quantities of highly enriched stable isotopes. The centrifuge may be used in stand-alone operation or could be used as a high-throughput pre-separation stage with calutrons providing the final separation.

  20. Demonstration of the enrichment of medium quality gas from gob wells through interactive well operating practices. Final report, June--December, 1995

    SciTech Connect (OSTI)

    Blackburn, S.T.; Sanders, R.G.; Boyer, C.M. II; Lasseter, E.L.; Stevenson, J.W.; Mills, R.A.

    1995-12-01T23:59:59.000Z

    Methane released to the atmosphere during coal mining operations is believed to contribute to global warming and represents a waste of a valuable energy resource. Commercial production of pipeline-quality gob well methane through wells drilled from the surface into the area above the gob can, if properly implemented, be the most effective means of reducing mine methane emissions. However, much of the gas produced from gob wells is vented because the quality of the gas is highly variable and is often below current natural gas pipeline specifications. Prior to the initiation of field-testing required to further understand the operational criteria for upgrading gob well gas, a preliminary evaluation and assessment was performed. An assessment of the methane gas in-place and producible methane resource at the Jim Walter Resources, Inc. No. 4 and No. 5 Mines established a potential 15-year supply of 60 billion cubic feet of mien methane from gob wells, satisfying the resource criteria for the test site. To understand the effect of operating conditions on gob gas quality, gob wells producing pipeline quality (i.e., < 96% hydrocarbons) gas at this site will be operated over a wide range of suction pressures. Parameters to be determined will include absolute methane quantity and methane concentration produced through the gob wells; working face, tailgate and bleeder entry methane levels in the mine; and the effect on the economics of production of gob wells at various levels of methane quality. Following this, a field demonstration will be initiated at a mine where commercial gob gas production has not been attempted. The guidelines established during the first phase of the project will be used to design the production program. The economic feasibility of various utilization options will also be tested based upon the information gathered during the first phase. 41 refs., 41 figs., 12 tabs.

  1. Design considerations for instrumentation to monitor the enrichment of gaseous UF{sub 6}

    SciTech Connect (OSTI)

    Close, D.A.

    1999-07-01T23:59:59.000Z

    The measurement of the enrichment of gaseous UF{sub 6} presents unique measurement problems. The well-known uranium enrichment meter is not applicable. For solid samples of uranium, including metal, and oxide and fluoride compounds, the infinite thickness is {approximately}1 cm. Gaseous UF{sub 6}, at a pressure of tens of Torr, has an infinite thickness on the order of 350 m. This is a physically and operationally unrealistic situation for an operating facility. Pipe dimensions and composition also strongly influence the applicable measurement technique. Fundamentally, the definition of enrichment is the ratio of {sup 235}U to total uranium. The amount of {sup 235}U is determined by measuring the intensity of the 185.7-keV gamma ray from the decay of {sup 235}U. There are two methods that have been implemented to determine the amount of total uranium in the gas: X-ray fluorescence (XRF) and gamma-ray transmission. The technique used to measure the amount of total uranium is dependent on the pressure of the gas in the header pipe. The transmission measurement is applicable for higher pressures, generally pressures {lt}40 Torr. The XRF measurement can be used for pressures greater than a few Torr. An XRF measurement at pressures lower than a few Torr becomes very difficult. Two other constraints strongly influence the implementation of the measurement technique--pipe diameter and material composition. These two techniques have been implemented. The XRF technique is an approved measurement by the International Atomic Energy Agency (IAEA) for inspections at gaseous centrifuge facilities. The XRF technique has also been implemented at the Portsmouth Gaseous Diffusion Plant for the IAEA verification experiment during the period December 1997 to October 1998 to verify the downblending of US highly enriched uranium (HEU) to low-enriched uranium (LEU). The transmission technique was originally developed to verify the downblending of Russian HEU to LEU. This instrument was demonstrated at the Paducah Gaseous Diffusion Plant from April 1998 to July 1998 and installed at the Urals Electrochemical Integrated Plant, Novouralsk, Russia, during January 1999.

  2. Centrifuge workers study. Phase II, completion report

    SciTech Connect (OSTI)

    Wooten, H.D.

    1994-09-01T23:59:59.000Z

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  3. Design guidelines for granular particles in a conical centrifugal filter

    E-Print Network [OSTI]

    Fleck, Norman A.

    Design guidelines for granular particles in a conical centrifugal filter A.F.M. Bizarda , D centrifugal filter is thereby obtained as a function of the slurry and basket properties. Corresponding basket) 1. Introduction 1.1. Centrifugal filters Centrifugal filters are commonly used in the food

  4. A methodology for centrifugal compressor stability prediction

    E-Print Network [OSTI]

    Benneke, Björn

    2009-01-01T23:59:59.000Z

    The stable operation of centrifugal compressors is limited by well-known phenomena, rotating stall and surge. Although the manifestation of the full scale instabilities is similar to the ones observed in axial machines, ...

  5. Improved return passages for multistage centrifugal compressors

    E-Print Network [OSTI]

    Glass, Benjamin W., S.M. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    This thesis presents a design concept for return passages in multistage centrifugal compressors. Flow in a baseline return passage is analyzed to identify loss sources that have substantial potential for reduction. For the ...

  6. EIS-0468: American Centrifuge Plant, Piketon, Ohio

    Broader source: Energy.gov [DOE]

    This EIS evaluates the environmental impacts of construction, operation, and decommissioning of the American Centrifuge Plant (ACP), located on DOE reservation in Piketon, Ohio. (DOE adopted this EIS issued by the Nuclear Regulatory Commission on 02/16/2011.)

  7. APPLICATION OF CENTRIFUGE MODELING IN GEOTECHNICAL ENGINEERING

    E-Print Network [OSTI]

    Kamat, Vineet R.

    properties) as its prototype, a principle of similitude may be established by the laws of mechanics may be obtained by substituting a centrifugal force to form the gravitational field, i.e., placing

  8. Static pushover analyses of pile groups in liquefied and laterally spreading ground in centrifuge tests

    E-Print Network [OSTI]

    Brandenberg, Scott J; Boulanger, R W; Kutter, Bruce L; Chang, Dongdong

    2007-01-01T23:59:59.000Z

    spreading ground during centrifuge tests. ” J. Geotech.and Liu, L. ?1995?. “Centrifuge modeling of liquefactionGonzales, L. ?2005?. “Centrifuge modeling of permeability

  9. DESIGN CHARACTERISTICS OF THE BOCHUM GEOTECHNICAL CENTRIFUGE AND POSSIBLE FIELDS OF RESEARCH

    E-Print Network [OSTI]

    Jessberger, Hans

    1984-01-01T23:59:59.000Z

    ADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held onl I I I Committee on Centrifuges of the International

  10. CRATERING MODEL VERIFICATION: A CENTRIFUGE PREDICTION VERSUS FIELD RESULT FOR A 40-TON EXPLOSIVE EVENT [abstract

    E-Print Network [OSTI]

    Holsapple, K.A.; Schmidt, R.M.

    1984-01-01T23:59:59.000Z

    and experiments on centrifuge crater- ing. J. Geophys. Res.J 980. Schmidt, R. M. , Centrifuge simulation of the JOHNIEformation - implications of centrifuge scaling. Proc. Lunar

  11. Evaluation of Nonlinear Site Response of Soft Clay Using Centrifuge Models

    E-Print Network [OSTI]

    Afacan, Kamil Bekir

    2014-01-01T23:59:59.000Z

    spreading ground during centrifuge tests." J. Geotech.densesand in laminated centrifuge container." J. Geotech. &response in laminated centrifuge container." Proc. 1st

  12. Behavior of Pile Foundations in Laterally Spreading Ground during Centrifuge Tests

    E-Print Network [OSTI]

    Brandenberg, Scott J; Boulanger, R W; Kutter, Bruce L; Chang, Dongdong

    2005-01-01T23:59:59.000Z

    during earthquakes: Centrifuge experiments and analyses. ”during earthquakes—centrifuge data report for SJB03. ” Rep.during earthquakes—centrifuge data report for SJB01. ” Rep.

  13. EVALUATION OF A CONSTITUTIVE MODEL FOR SOFT CLAY USING THE CENTRIFUGE

    E-Print Network [OSTI]

    Liang, R.Y.K.; Tse, E.C.; Kuhn, M.R.; Mitchell, J.K.

    1984-01-01T23:59:59.000Z

    gravity field in the centrifuge is radial and the verticalADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held on

  14. Supernova Enrichment of Dwarf Spheroidal Galaxies

    E-Print Network [OSTI]

    P. Chris Fragile; Stephen D. Murray; Peter Anninos; Douglas N. C. Lin

    2003-03-10T23:59:59.000Z

    (Abridged) Many dwarf galaxies exhibit sub-Solar metallicities, with some star-to-star variation, despite often containing multiple generations of stars. The total metal content in these systems is much less than expected from the heavy element production of massive stars in each episode of star formation. Such a deficiency implies that a substantial fraction of the enriched material has been lost from these small galaxies. Mass ejection from dwarf galaxies may have important consequences for the evolution of the intergalactic medium and for the evolution of massive galaxies, which themselves may have formed via the merger of smaller systems. We report here the results of three-dimensional simulations of the evolution of supernova-enriched gas within dwarf spheroidal galaxies (dSph's), with the aim of determining the retention efficiency of supernova ejecta. We consider two galaxy models, selected to represent opposite ends of the dSph sequence. For each model galaxy we investigate a number of scenarios, ranging from a single supernova in smooth gas distributions to more complex multiple supernovae in highly disturbed gas distributions. The results of these investigations suggest that, for low star-formation efficiencies, it is difficult to completely expel the enriched material from the galaxy. Most of the enriched gas is, however, lost from the core of the galaxy following multiple supernovae, especially if the interstellar medium is already highly disturbed by processes such as photo-ionization and stellar winds. If subsequent star formation occurs predominantly within the core where most of the residual gas is concentrated, then these results could explain the poor self-enrichment efficiency observed in dwarf galaxies.

  15. Glycoprotein Enrichment Resin User Manual

    E-Print Network [OSTI]

    Lebendiker, Mario

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

  16. The geotechnical centrifuge in offshore engineering

    SciTech Connect (OSTI)

    Murff, J.D.

    1996-12-31T23:59:59.000Z

    One of the greatest needs in offshore geotechnical engineering is for large scale test measurements on which to calibrate design procedures. The geotechnical centrifuge offers at least a partial remedy. Because it allows one to properly simulate stresses, it is a legitimate, relatively inexpensive option to full scale field testing. As such it is a valuable technique and can be an excellent complement to laboratory tests, 1-g model tests and numerical analyses. However, it has not been widely used by industry even though the capability has existed for almost thirty years. This paper argues that this technology should gain acceptance beyond the research community. The paper presents an overview of centrifuge principles, philosophies of use, and limitations of the technique. For illustration, several actual applications of centrifuge testing for complex offshore problems are described. Results are shown to provide important insights into prototype behavior and to agree well with full scale measurements where these are available.

  17. Development of a body force model for centrifugal compressors

    E-Print Network [OSTI]

    Kottapalli, Anjaney Pramod

    2013-01-01T23:59:59.000Z

    This project is focused on modeling the internal ow in centrifugal compressors for the purpose of assessing the onset of rotating stall and surge. The current methods to determine centrifugal compressor stability limits ...

  18. A parametric study of vestibular stimulation during centrifugation

    E-Print Network [OSTI]

    Pouly, Jeremie M

    2006-01-01T23:59:59.000Z

    Artificial Gravity (AG) provided by short-radius centrifugation is a promising countermeasure to the health problems associated with long duration human spaceflight. Head-turns performed during centrifugation, however, ...

  19. Isotope Enrichment Detection by Laser Ablation - Laser Absorption Spectrometry: Automated Environmental Sampling and Laser-Based Analysis for HEU Detection

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2010-01-01T23:59:59.000Z

    The global expansion of nuclear power, and consequently the uranium enrichment industry, requires the development of new safeguards technology to mitigate proliferation risks. Current enrichment monitoring instruments exist that provide only yes/no detection of highly enriched uranium (HEU) production. More accurate accountancy measurements are typically restricted to gamma-ray and weight measurements taken in cylinder storage yards. Analysis of environmental and cylinder content samples have much higher effectiveness, but this approach requires onsite sampling, shipping, and time-consuming laboratory analysis and reporting. Given that large modern gaseous centrifuge enrichment plants (GCEPs) can quickly produce a significant quantity (SQ ) of HEU, these limitations in verification suggest the need for more timely detection of potential facility misuse. The Pacific Northwest National Laboratory (PNNL) is developing an unattended safeguards instrument concept, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely analysis of enrichment levels within low enriched uranium facilities. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy to characterize the uranium isotopic ratio through subtle differences in atomic absorption wavelengths. Environmental sampling (ES) media from an integrated aerosol collector is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes material from a 10 to 20-µm diameter spot of the surface of the sampling media. The plume of ejected material begins as high-temperature plasma that yields ions and atoms, as well as molecules and molecular ions. We concentrate on the plume of atomic vapor that remains after the plasma has expanded and then cooled by the surrounding cover gas. Tunable diode lasers are directed through this plume and each isotope is detected by monitoring absorbance signals on a shot-to-shot basis. The media is translated by a micron resolution scanning system, allowing the isotope analysis to cover the entire sample surface. We also report, to the best of our knowledge, the first demonstration of laser-based isotopic measurements on individual micron-sized particles that are minor target components in a much larger heterogeneous mix of ‘background’ particles. This composition is consistent with swipe and environmental aerosol samples typically collected for safeguards ES purposes. Single-shot detection sensitivity approaching the femtogram range and relative isotope abundance uncertainty better than 10% has been demonstrated using gadolinium isotopes as surrogate materials.

  20. EIS-0468: American Centrifuge Plant in Piketon, OH | Department...

    Broader source: Energy.gov (indexed) [DOE]

    May 20, 2011 EIS-0468: Final Environmental Impact Statement Proposed American Centrifuge Plant in Piketon, Ohio Pike County, Ohio...

  1. Testing of Expansive Clays in a Centrifuge Permeameter

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    Testing of Expansive Clays in a Centrifuge Permeameter M. D. Plaisted & J. G. Zornberg with the objective of characterizing the swelling of highly plastic clays using a centrifuge permeameter. The new. This study, conducted using a comparatively simple, non- instrumented centrifuge device complements ongo- ing

  2. The Problem with Continuity of Knowledge in Enrichment Plant Process Monitoring

    SciTech Connect (OSTI)

    Curtis, Michael M.

    2009-08-01T23:59:59.000Z

    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.

  3. Submarine landslide flows simulation through centrifuge modelling

    E-Print Network [OSTI]

    Gue, Chang Shin

    2012-05-08T23:59:59.000Z

    ......... 140   4.6.4   Series 4: Experiments at various g le vels with a large flow rate in the dry condition ........................................................................................ 148   4.7   Repeatability of the Centrifuge Experiments... .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188   5.5.4   Side wall friction ..................................................................................189   5.5.5   Basal friction and pore pressure ratio ( ? ) ............................................ 194   5.6   Summary...

  4. Differential white cell count by centrifugal microfluidics.

    SciTech Connect (OSTI)

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01T23:59:59.000Z

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  5. Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

    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.

  6. Concentration of carbon types from fly ash by density gradient centrifugation

    SciTech Connect (OSTI)

    Maroto-Valer, M.M.; Taulbee, D.N.; Hower, J.C. [Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1998-12-31T23:59:59.000Z

    Although the increasing amount of unburned carbon in fly ash is known to preclude the use of ash in the cement industry, very little is known about the characteristics of the unburned carbon. Three types of carbon particles have been identified microscopically: inertinite, isotropic coke and anisotropic coke. This manuscript describes a method to isolate these three types of carbon. A preliminary enrichment, followed by density gradient centrifugation (DGC) with a high-density polytungstate media (2.85 g/cm{sup 3} max), resulted in an enrichment of inertinites from a starting concentration of 3.8% to 61%, isotropic coke from 13.4% to 65%, and anisotropic coke from 19.2% to 74%. Large scale runs (LS) have been conducted to accumulate sufficient sample for subsequent analyses. The recovery weights and petrography composition of the PS and LS fractions are very similar.

  7. TECH REPORT Enrichment analysis of

    E-Print Network [OSTI]

    Chait, Brian T.

    TECH REPORT Enrichment analysis of phosphorylated proteins as a tool for probing of relatively abundant proteins2,3. Therefore, for effective proteome analysis it becomes critical to enrich substrates can be greatly enhanced by enriching the sample of phosphorylated proteins. Although enrichment

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

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2010-04-15T23:59:59.000Z

    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

  9. Effects of vaned diffuser pressure recovery on centrifugal compressor stage performance

    E-Print Network [OSTI]

    Eason, Robyn Monique

    1985-01-01T23:59:59.000Z

    Orientation of Channel Taps and Sealed Holes ? ? ? ? ? 28 11 Control Rxan 12 Inlet and Exit Velocity Triangles 13 Impeller Meridional Profile- 14 Prescribed Flow Functians 30 35 36 15 Vened Diffuser Geanetry 41 16 Leading Edge Circumf erentia1 Static... of vened diffuser static pressure recovery on centrifugal ccxn- pressor stage performance are presented. A single-stage radial canpres- sor experiencing actual operating conditions in a Ford regenerative gas turbine engine was utilized...

  10. Feedback and metal enrichment in cosmological SPH simulations I. A model for chemical enrichment

    E-Print Network [OSTI]

    C. Scannapieco; P. B. Tissera; S. D. M. White; V. Springel

    2006-07-10T23:59:59.000Z

    We discuss a model for treating chemical enrichment by SNII and SNIa explosions in simulations of cosmological structure formation. Our model includes metal-dependent radiative cooling and star formation in dense collapsed gas clumps. Metals are returned into the diffuse interstellar medium by star particles using a local SPH smoothing kernel. A variety of chemical abundance patterns in enriched gas arise in our treatment owing to the different yields and lifetimes of SNII and SNIa progenitor stars. In the case of SNII chemical production, we adopt metal-dependent yields. Because of the sensitive dependence of cooling rates on metallicity, enrichment of galactic haloes with metals can in principle significantly alter subsequent gas infall and the build up of the stellar components. Indeed, in simulations of isolated galaxies we find that a consistent treatment of metal-dependent cooling produces 25% more stars outside the central region than simulations with a primordial cooling function. In the highly-enriched central regions, the evolution of baryons is however not affected by metal cooling, because here the gas is always dense enough to cool. A similar situation is found in cosmological simulations because we include no strong feedback processes which could spread metals over large distances and mix them into unenriched diffuse gas. We demonstrate this explicitly with test simulations which adopt super-solar cooling functions leading to large changes both in the stellar mass and in the metal distributions. We also find that the impact of metallicity on the star formation histories of galaxies may depend on their particular evolutionary history. Our results hence emphasise the importance of feedback processes for interpreting the cosmic metal enrichment.

  11. A vibration model for centrifugal contactors

    SciTech Connect (OSTI)

    Leonard, R.A.; Wasserman, M.O.; Wygmans, D.G.

    1992-11-01T23:59:59.000Z

    Using the transfer matrix method, we created the Excel worksheet ``Beam`` for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k{sub B}) of a motor after measuring the k{sub B} value for three different motors. The k{sub B} value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.

  12. Wave-driven Countercurrent Plasma Centrifuge

    SciTech Connect (OSTI)

    A.J. Fetterman and N.J. Fisch

    2009-03-20T23:59:59.000Z

    A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the ? channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow pattern using waves instead of electrodes, physical and engineering issues may be avoided.

  13. Free of centrifugal acceleration spacetime - Geodesics

    E-Print Network [OSTI]

    Hristu Culetu

    2013-04-27T23:59:59.000Z

    A static spacetime with no centrifugal repulsion, previously studied by Dadhich, is investigate in this paper. The source of curvature is considered to be an anisotropic fluid with $\\rho = -p_{r}$ and constant angular pressures. The positive parameter from the line-element is interpreted as the invariant acceleration of a static observer. We found that the Tolman-Komar gravitational energy is finite everywhere. The timelike and null geodesics of the spacetime are examined.

  14. Centrifugal shot blasting. Innovative technology summary report

    SciTech Connect (OSTI)

    Not Available

    1999-07-01T23:59:59.000Z

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

  15. Improving the efficiency of centrifugal fans

    E-Print Network [OSTI]

    Wolfe, Clifford Kent

    1976-01-01T23:59:59.000Z

    P s static pressure corrected to fan outlet H2O Nomenclature (cont. ) Symbol Description Units p ~ N? N et e s S hp pressure corrected to specified speed and standard air density specified speed test fan speed total (mechanical...) efficiency static efficiency specific horsepower in. H 0 RPN RPN hp CHAPTER I INTRODUCTION The uses of centrifugal (squirrel cage) fans in our nation range from air conditioning in our homes to exhausting fumes from industrial plants. Because...

  16. Isotopically Enriched Films and Nanostructures by Ultrafast Pulsed Laser Deposition

    SciTech Connect (OSTI)

    Peter Pronko

    2004-12-13T23:59:59.000Z

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

  17. Enrichment of the Intracluster Medium

    E-Print Network [OSTI]

    D. Thomas

    1998-11-25T23:59:59.000Z

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

  18. Enrichment short courses and special

    E-Print Network [OSTI]

    Enrichment short courses and special events specially developed for folks 50 and better. Look better way to spend your summer than expanding your knowledge and enriching your life with an Osher

  19. An investigation of the bearing capacity of footings under eccentric and inclined loading on sand in a geotechnical centrifuge

    E-Print Network [OSTI]

    James, R.G.; Tanaka, H.

    1984-01-01T23:59:59.000Z

    The application of centrifuge modelling to geotechnicalADVANCES IN GEOTECHNICAL CENTRIFUGE MODELING A symposium onAdvances in Geotechnical Centrifuge Modeling was held on

  20. A curious spacetime entirely free of centrifugal acceleration

    E-Print Network [OSTI]

    Naresh Dadhich

    2012-09-07T23:59:59.000Z

    In the Einstein gravity, besides the usual gravitational and centrifugal potential there is an additional attractive term that couples these two together. It is fun to enquire whether the latter could fully counteract the centrifugal repulsion everywhere making the spacetime completely free of the centrifugal acceleration. We present here such a curious spacetime metric and it produces a global monopole like stresses going as $~1/r^2$ in an AdS spacetime.

  1. Control Strategies for Centrifugal Pumps with Variable Flow Rate...

    Broader source: Energy.gov (indexed) [DOE]

    This tip sheet discusses control strategies for centrifugal pumps with variable flow rate requirements in pumping systems and includes installation considerations. PUMPING SYSTEMS...

  2. Exercise protocols during short-radius centrifugation for artificial gravity

    E-Print Network [OSTI]

    Edmonds, Jessica Leigh

    2008-01-01T23:59:59.000Z

    Long-duration spaceflight results in severe physiological deconditioning, threatening the success of interplanetary travel. Exercise combined with artificial gravity provided by centrifugation may be the comprehensive ...

  3. Incremental adaptation to yaw head movements during 30 RPM centrifugation

    E-Print Network [OSTI]

    Elias, Paul Z. (Paul Ziad)

    2006-01-01T23:59:59.000Z

    Artificial Gravity (AG) provided by short-radius centrifugation is a promising countermeasure against the harmful physiological effects of prolonged weightlessness. However, the vestibular stimulus associated with making ...

  4. anion exchange centrifugation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of a Centrifuged Double Y-Shape Microfluidic Platform for Simple Continuous Cell Environment Exchange CiteSeer Summary: Abstract: We have demonstrated the efficacy of a...

  5. Self-enrichment in Omega Centauri

    E-Print Network [OSTI]

    C. Ikuta; N. Arimoto

    1999-12-28T23:59:59.000Z

    The origin of abundance spreads observed in omega Centauri is studied in the context of the self-enrichment scenario. Five chemical evolution models are constructed and are compared with empirical metallicity distribution of $\\omega$ Cen. After a series of simulations, it is found that neither of closed-box, outflow, nor infall models can reproduce the empirical metallicity distribution of omega Cen, while a modified outflow model with a bimodal initial mass function (IMF) gives a metallicity distribution that fits closely to the empirical ones. In the modified outflow model, long-lived stars are assumed to form after the first explosion of type II supernovae (SNII) in a proto-cloud. The modified outflow model involves gas infall at the very first chemical evolution. Thus we conclude that self-enrichment causes the abundance dispersion in omega Cen. A success of the outflow model with the bimodal IMF implies that low mass stars in a globular cluster (GC) should have formed in the gas already enriched by the first generation of SNII. This scenario, originally proposed by Cayrel (1986), can explain a lack of globular clusters with [Fe/H] > -2.2 in the Milky Way Galaxy.

  6. Proceedings of the Symposium on Recent Advances in Geotechnical Centrifuge Modeling

    E-Print Network [OSTI]

    Center for Geotechnical Modeling, Department of Civil Engineering, University of California Davis

    1984-01-01T23:59:59.000Z

    S. Bang and J.F. Mitchell, "Centrifuge Modeling of a LateralJ.A. Cheney, "Drum Centrifuge Studies of Overconsolidatedand R.H. Bassett, "Centrifuge Testing in Geotechnical

  7. FACTORS IN THE DESIGN OF A ROCK MECHANICS CENTRIFUGE FOR STRONG ROCK

    E-Print Network [OSTI]

    Clark, George B

    1984-01-01T23:59:59.000Z

    1 . Capacit i es of known centrifuges and v proposed SoftSolla I rock mechanics centrifuge r, ---------1~ --- dxB. , (1980), Geotechnical centrifuges for model studies and

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

    SciTech Connect (OSTI)

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

    2010-05-28T23:59:59.000Z

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

  9. Drive torque actuation in active surge control of centrifugal compressors

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Drive torque actuation in active surge control of centrifugal compressors Jan Tommy Gravdahl , Olav to active surge control is presented for a centrifugal compressor driven by an electrical motor. The main is considered to be the control input. The proposed method is simulated on a compressor model using

  10. Active surge control of centrifugal compressors using drive torque

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Active surge control of centrifugal compressors using drive torque Jan Tommy Gravdahl , Olav control is presented. A centrifugal compressor driven by an electrical motor is studied, and the drive of the drive as control ensures exponential convergence. The proposed method is simulated on a compressor model

  11. Thermal breeder fuel enrichment zoning

    DOE Patents [OSTI]

    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)

    1992-01-01T23:59:59.000Z

    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.

  12. Gas Turbine Technology, Part B: Components, Operations and Maintenance

    E-Print Network [OSTI]

    Meher-Homji, C. B.; Focke, A. B.

    , single and split shaft. The pros and cons of different types are reviewed. Gas turbine component types - axial and centrifugal compressors and different turbine types, along with combustor types will be discussed. Important considerations during machine...

  13. An investigation of real gas effects in supercritical CO? compressors

    E-Print Network [OSTI]

    Baltadjiev, Nikola D. (Nikola Dimitrov)

    2012-01-01T23:59:59.000Z

    This thesis presents a comprehensive assessment of real gas effects on the performance and matching of centrifugal compressors operating with CO2 at supercritical conditions. The analytical framework combines first principles ...

  14. The Enrichment of the Intracluster Medium

    E-Print Network [OSTI]

    Brad K. Gibson; Francesca Matteucci

    1996-12-13T23:59:59.000Z

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

  15. High-temperature gas-cooled reactors: preliminary safety and environmental information document. Volume IV

    SciTech Connect (OSTI)

    Not Available

    1980-01-01T23:59:59.000Z

    Information is presented concerning medium-enriched uranium/thorium once-through fuel cycle; medium-enrichment uranium-233/thorium recycle fuel; high-enrichment uranium-235/thorium recycle (spiked) fuel cycle; high-enrichment uranium-233/thorium recycle (spiked) fuel cycle; and gas-turbine high-temperature gas-cooled reactor.

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

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2009-07-01T23:59:59.000Z

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

  17. Chemical Enrichment from Massive Stars in Starbursts

    E-Print Network [OSTI]

    Henry A. Kobulnicky

    1999-01-20T23:59:59.000Z

    The warm ionized gas in low-mass, metal-poor starforming galaxies is chemically homogeneous despite the prevalence of large H II regions which contain hundreds of evolved massive stars, supernovae, and Wolf-Rayet stars with chemically-enriched winds. Galaxies with large Wolf-Rayet star content are chemically indistinguishable from other vigorously star-forming galaxies. Furthermore, no significant localized chemical fluctuations are present in the vicinity of young star clusters, despite large expected chemical yields of massive stars. An ad-hoc fine-tuning of the release, dispersal and mixing of the massive star ejecta could give rise to the observed homogeneity, but a more probable explanation is that fresh ejecta from massive stars reside in a hard-to-observe hot or cold phase. In any case, the observed chemical homogeneity indicates that heavy elements which have already mixed with the warm interstellar medium (thus accessible to optical spectroscopy) are homogeneously dispersed over scales exceeding 1 kpc. Mixing of fresh ejecta with the surrounding warm ISM apparently requires longer than the lifetimes of typical H II regions (>10^7 yrs). The lack of observed localized chemical enrichments is consistent with a scenario whereby freshly-synthesized metals from massive stars are expelled into the halos of galaxies in a hot, 10^6 K phase by supernova-driven winds before they cool and ``rain'' back down upon the galaxy, creating gradual enrichments on spatial scales >1 kpc.

  18. LES of a Hydrogen-Enriched Lean Turbulent Premixed Flame

    E-Print Network [OSTI]

    Groth, Clinton P. T.

    LES of a Hydrogen-Enriched Lean Turbulent Premixed Flame Francisco E. Hern´andez-P´erez , Clinton the observed behaviour is examined. Hydrogen-hydrocarbon fuel blends appear to be a promising option to synergistically pave the way toward pure hydrogen-based combustion systems while alleviating green-house gas

  19. Third International Meeting on Next Generation Safeguards:Safeguards-by-Design at Enrichment Facilities

    SciTech Connect (OSTI)

    Long, Jon D. [Y-12 National Security Complex] [Y-12 National Security Complex; McGinnis, Brent R [ORNL] [ORNL; Morgan, James B [ORNL] [ORNL; Whitaker, Michael [ORNL] [ORNL; Lockwood, Mr. Dunbar [U.S. Department of Energy, NNSA] [U.S. Department of Energy, NNSA; Shipwash, Jacqueline L [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The Third International Meeting on Next Generation Safeguards (NGS3) was hosted by the U.S. Department of Energy (DOE)/National Nuclear Security Administration's (NNSA) Office of Nonproliferation and International Security (NIS) in Washington, D.C. on 14-15 December 2010; this meeting focused on the Safeguards-by-Design (SBD) concept. There were approximately 100 participants from 13 countries, comprised of safeguards policy and technical experts from government and industry. Representatives also were present from the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC), the European Atomic Energy Agency (Euratom), and the International Atomic Energy Agency (IAEA). The primary objective of this meeting was to exchange views and provide recommendations on implementation of the SBD concept for four specific nuclear fuel cycle facility types: gas centrifuge enrichment plants (GCEPs), GEN III and GEN IV reactors, aqueous reprocessing plants, and mixed oxide fuel fabrication facilities. The general and facility-specific SBD documents generated from the four working groups, which were circulated for comment among working group participants, are intended to provide a substantive contribution to the IAEA's efforts to publish SBD guidance for these specific types of nuclear facilities in the near future. The IAEA has described the SBD concept as an approach in which 'international safeguards are fully integrated into the design process of a new nuclear facility from the initial planning through design, construction, operation, and decommissioning.' As part of the Next Generation Safeguards Initiative (NGSI), the DOE is working to establish SBD as a global norm through DOE laboratory studies, international workshops, engagement with industry and the IAEA, and setting an example through its use in new nuclear facilities in the United States. This paper describes the discussion topics and final recommendations of the Enrichment Facilities Working Group. The working group participants were tasked with providing recommendations for facility operators and designers, while promoting the IAEA's objectives of: (1) avoiding costly and time-consuming redesign work or retrofits of new nuclear facilities and (2) providing for more effective and efficient implementation of international safeguards.

  20. Pragmatically enriching and 1 Children's enrichments of conjunctive sentences in context

    E-Print Network [OSTI]

    Institut des Sciences Cognitives, CNRS

    Pragmatically enriching and 1 Children's enrichments of conjunctive sentences in context Ira Noveck Rutgers University Lewis Bott Cardiff University RUNNING HEAD: Pragmatically enriching and #12;Pragmatically enriching and 2 Abstract An utterance conjoining two propositions with and often conveys more

  1. Generic Enrichment Plan Enrichment plans exist to promote the psychological well-being of laboratory animals.

    E-Print Network [OSTI]

    Bandettini, Peter A.

    Generic Enrichment Plan Enrichment plans exist to promote the psychological well An integrated approach to behavioral management should include: 1) Environmental Enrichment a) Elements of enrichment b) Implementation processes 2) Behavioral Management a) Identifying and treating animals

  2. Calibration of accelerometers on the 1000 g centrifuge

    SciTech Connect (OSTI)

    Rebarchik, F.N.

    1991-04-01T23:59:59.000Z

    This memorandum is a synopsis of the description and operation of the equipment used, and the events occurring during the calibration of an accelerometer on the 1000 G centrifuge. 2 refs., 1 tab.

  3. Characterization of unsteady flow processes in a centrifugal compressor stage

    E-Print Network [OSTI]

    Gould, Kenneth A. (Kenneth Arthur)

    2006-01-01T23:59:59.000Z

    Numerical experiments have been implemented to characterize the unsteady loading on the rotating impeller blades in a modem centrifugal compressor. These consist of unsteady Reynolds-averaged Navier Stokes simulations of ...

  4. Centrifugal compressor return channel shape optimization using adjoint method

    E-Print Network [OSTI]

    Guo, Wei, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    This thesis describes the construction of an automated gradient-based optimization process using the adjoint method and its application to centrifugal compressor return channel loss reduction. A proper objective function ...

  5. Centrifuge modeling of LNAPL transport in partially saturated sand

    SciTech Connect (OSTI)

    Esposito, G.; Allersma, H.G.B.; Selvadurai, A.P.S.

    1999-12-01T23:59:59.000Z

    Model tests were performed at the Geotechnical Centrifuge Facility of Delft University of Technology, The Netherlands, to examine the mechanics of light nonaqueous phase liquid (LNAPL) movement in a partially saturated porous granular medium. The experiment simulated a 2D spill of LNAPL in an unsaturated sand prepared at two values of porosity. The duration of the centrifuge model tests corresponded to a prototype equivalent of 110 days. The choice of modeling a 2D flow together with the use of a transparent container enabled direct visual observation of the experiments. Scaling laws developed in connection with other centrifuge modeling studies were used to support the test results. Tests were conducted at two different centrifuge accelerations to verify, by means of the modeling of models technique, the similitude between the different experiments. The paper presents details of the experimental methodologies and the measuring techniques used to evaluate the final distribution of water and LNAPL content in the soils.

  6. Improved screen-bowl centrifuge recovery using polymer injection technology

    SciTech Connect (OSTI)

    Burchett, R.T.; McGough, K.M.; Luttrell, G.H.

    2006-08-15T23:59:59.000Z

    The paper reports the improved screen-bowl centrifuge recovery process using polymer injection technology. Field test and economic analysis are also included in the paper. 3 refs., 3 figs., 1 tab.

  7. Calibration of accelerometers on the 5000 g centrifuge

    SciTech Connect (OSTI)

    Rebarchik, F.N.

    1992-05-01T23:59:59.000Z

    This memorandum is a synopsis of the description and operation of the equipment used and the events occurring during the calibration of an accelerometer on the 5000 g centrifuge.

  8. Cross plane transfer of vestibular adaptation to human centrifugation

    E-Print Network [OSTI]

    Garrick-Bethell, Ian, 1980-

    2004-01-01T23:59:59.000Z

    Human short-radius centrifugation (SRC) is being investigated as a volume-efficient means of delivering intermittent doses of "artificial gravity" to counter the deleterious effects of long exposures to weightlessness. ...

  9. Multi-parameter control for centrifugal compressor performance optimization

    E-Print Network [OSTI]

    Mannai, Sébastien (Sébastien Karim)

    2014-01-01T23:59:59.000Z

    The potential performance benefit of actuating inlet guide vane (IGV) angle, variable diffuser vane (VDV) angle and impeller speed to implement a multi-parameter control on a centrifugal compressor system is assessed. The ...

  10. Forced response predictions in modern centrifugal compressor design

    E-Print Network [OSTI]

    Smythe, Caitlin J. (Caitlin Jeanne)

    2005-01-01T23:59:59.000Z

    A computational interrogation of the time-averaged and time-unsteady flow fields of two centrifugal compressors of nearly identical design (the enhanced, which encountered aeromechanical difficulty, and production, which ...

  11. Squat exercise biomechanics during short-radius centrifugation

    E-Print Network [OSTI]

    Duda, Kevin R., 1979-

    2007-01-01T23:59:59.000Z

    Artificial gravity (AG) created by short-radius centrifugation is a promising countermeasure to the physiological de-conditioning that results from long-duration spaceflight. However, as on Earth, gravity alone does not ...

  12. Algal Harvesting for Biodiesel Production: Comparing Centrifugation and Electrocoagulation

    E-Print Network [OSTI]

    Kovalcik, Derek John

    2013-08-09T23:59:59.000Z

    Electrocoagulation was compared to centrifugation at pilot scale for harvesting Nannochloris oculata and Nannochloropsis salina for biodiesel production. The pilot scale testing is a proof of concept and no optimization was conducted. Testing used...

  13. Single stage high pressure centrifugal slurry pump

    DOE Patents [OSTI]

    Meyer, John W. (Palo Alto, CA); Bonin, John H. (Sunnyvale, CA); Daniel, Arnold D. (Alameda, CA)

    1984-03-27T23:59:59.000Z

    Apparatus is shown for feeding a slurry to a pressurized housing. An impeller that includes radial passages is mounted in the loose fitting housing. The impeller hub is connected to a drive means and a slurry supply means which extends through the housing. Pressured gas is fed into the housing for substantially enveloping the impeller in a bubble of gas.

  14. A method of predicting surge in centrifugal compressors

    E-Print Network [OSTI]

    Elchuri, Vijayvardhan

    1975-01-01T23:59:59.000Z

    A METHOD OF PREDICTING SURGE IN CENTRIFUGAL COMPRESSORS A Thesis by VIJAYVARDHAN FLCHURI Submitted to the Graduate College of Texas A6? University in nartial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1975... Major Subject Mechanical Enpineerinp A METHOD OF PREDICTING SURGE IN CENTRIFUGAL COMPRESSORS A Thesis by VIJAYVARDHAN ELCHURI Approved as to style and content by: Chairman o Committee Hea o partment Mem er m er Mem er I , 0, em er Mem er...

  15. Estimation of capillary pressure functions from centrifuge data

    E-Print Network [OSTI]

    Dulaney, William Proby

    1986-01-01T23:59:59.000Z

    ESTIMATION OF CAPILLARY PRESSURE FUNCTIONS FROM CENTRIFUGE DATA A Thesis by WILLIAM PBOIIY DULANEY, IR. Submitted to the Graduate College of Texas A8 M University in partial fulfillment, of the requirement for the degree of MASTER OF SCIENCF.... Ta. ttcrson (Member) C. B. Holland (Head of Department) C. H. Wu (Member) May 1986 AI3STRACT Lstimation of Capillary Pressure Functions From Centrifuge Data. (May 1986) William Proby Dulaney Jr. , B. S. , Mississippi Sta4e University...

  16. Graduate Senate Professional Enrichment Grant Application System

    E-Print Network [OSTI]

    Stuart, Steven J.

    Graduate Senate Professional Enrichment Grant Application System (PEGAS) Committee Rules a Frequently Asked Questions section on the Professional Enrichment Grant Application Service (PEGAS) webpage outlining common questions on Professional Enrichment Grants (PEG) applications. Rule II. Committee

  17. Sonication-based isolation and enrichment of Chlorella protothecoides chloroplasts for illumina genome sequencing

    SciTech Connect (OSTI)

    Angelova, Angelina [University of Arizona; Park, Sang-Hycuk [University of Arizona; Kyndt, John [Bellevue University; Fitzsimmons, Kevin [University of Arizona; Brown, Judith K [University of Arizona

    2013-09-01T23:59:59.000Z

    With the increasing world demand for biofuel, a number of oleaginous algal species are being considered as renewable sources of oil. Chlorella protothecoides Krüger synthesizes triacylglycerols (TAGs) as storage compounds that can be converted into renewable fuel utilizing an anabolic pathway that is poorly understood. The paucity of algal chloroplast genome sequences has been an important constraint to chloroplast transformation and for studying gene expression in TAGs pathways. In this study, the intact chloroplasts were released from algal cells using sonication followed by sucrose gradient centrifugation, resulting in a 2.36-fold enrichment of chloroplasts from C. protothecoides, based on qPCR analysis. The C. protothecoides chloroplast genome (cpDNA) was determined using the Illumina HiSeq 2000 sequencing platform and found to be 84,576 Kb in size (8.57 Kb) in size, with a GC content of 30.8 %. This is the first report of an optimized protocol that uses a sonication step, followed by sucrose gradient centrifugation, to release and enrich intact chloroplasts from a microalga (C. prototheocoides) of sufficient quality to permit chloroplast genome sequencing with high coverage, while minimizing nuclear genome contamination. The approach is expected to guide chloroplast isolation from other oleaginous algal species for a variety of uses that benefit from enrichment of chloroplasts, ranging from biochemical analysis to genomics studies.

  18. 99.996 %{sup 12}C films isotopically enriched and deposited in situ

    SciTech Connect (OSTI)

    Dwyer, K. J. [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States) [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States); Pomeroy, J. M.; Simons, D. S. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)

    2013-06-24T23:59:59.000Z

    Ionizing natural abundance carbon dioxide gas, we extract and mass select the ions, depositing thin films isotopically enriched to 99.9961(4) %{sup 12}C as measured by secondary ion mass spectrometry (SIMS). In solid state quantum information, coherence times of nitrogen-vacancy (NV) centers in {sup 12}C enriched diamond exceeding milliseconds demonstrate the viability of NV centers as qubits, motivating improved isotopic enrichment. NV centers in diamond are particularly attractive qubit candidates due to the optical accessibility of the spin states. We present SIMS analysis and cross-sectional scanning electron microscopy of {sup 12}C enriched thin film samples grown with this method.

  19. High-purity, isotopically enriched bulk silicon

    E-Print Network [OSTI]

    2004-01-01T23:59:59.000Z

    Russia. The stated isotope enrichments are summarized inenrichments >99% have been achieved for each isotope andthe enrichment is highest, are presented. isotope at. % nat.

  20. Disposition of Surplus Highly Enriched Uranium

    Broader source: Energy.gov (indexed) [DOE]

    of Surplus Highly Enriched Uranium Environmental Impact Statement kternationd Atomic Energy Agency Idaho Nationrd Engineering Laborato low-enriched uranium low-level waste...

  1. Uranium Enrichment Decontamination and Decommissioning Fund's...

    Office of Environmental Management (EM)

    Uranium Enrichment Decontamination and Decommissioning Fund's Fiscal Year 2008 and 2007 Financial Statement Audit, OAS-FS-10-05 Uranium Enrichment Decontamination and...

  2. Fuel Effects on a Low-Swirl Injector for Lean Premixed Gas Turbines

    E-Print Network [OSTI]

    Littlejohn, David

    2008-01-01T23:59:59.000Z

    equivalent to those from landfill gas to liquified petroleumlandfill and biomass fuels, H 2 -enriched CH 4 to simulate refinery gas

  3. An Optically Stimulated Luminescence Uranium Enrichment Monitor

    SciTech Connect (OSTI)

    Miller, Steven D.; Tanner, Jennifer E.; Simmons, Kevin L.; Conrady, Matthew M.; Benz, Jacob M.; Greenfield, Bryce A.

    2010-08-11T23:59:59.000Z

    The Pacific Northwest National Laboratory (PNNL) has pioneered the use of Optically Stimulated Luminescence (OSL) technology for use in personnel dosimetry and high dose radiation processing dosimetry. PNNL has developed and patented an alumina-based OSL dosimeter that is being used by the majority of medical X-ray and imaging technicians worldwide. PNNL has conceived of using OSL technology to passively measure the level of UF6 enrichment by attaching the prototype OSL monitor to pipes containing UF6 gas within an enrichment facility. The prototype OSL UF6 monitor utilizes a two-element approach with the first element open and unfiltered to measure both the low energy and high energy gammas from the UF6, while the second element utilizes a 3-mm thick tungsten filter to eliminate the low energy gammas and pass only the high energy gammas from the UF6. By placing a control monitor in the room away from the UF6 pipes and other ionizing radiation sources, the control readings can be subtracted from the UF6 pipe monitor measurements. The ratio of the shielded to the unshielded net measurements provides a means to estimate the level of uranium enrichment. PNNL has replaced the commercially available MicroStar alumina-based dosimeter elements with a composite of polyethylene plastic, high-Z glass powder, and BaFBr:Eu OSL phosphor powder at various concentrations. The high-Z glass was added in an attempt to raise the average “Z” of the composite dosimeter and increase the response. Additionally, since BaFBr:Eu OSL phosphor is optimally excited and emits light at different wavelengths compared to alumina, the commercially available MicroStar reader was modified for reading BaFBr:Eu in a parallel effort to increase reader sensitivity. PNNL will present the design and performance of our novel OSL uranium enrichment monitor based on a combination of laboratory and UF6 test loop measurements. PNNL will also report on the optimization effort to achieve the highest possible performance from both the OSL enrichment monitor and the new custom OSL reader modified for this application. This project has been supported by the US Department of Energy’s National Nuclear Security Administration’s Office of Dismantlement and Transparency (DOE/NNSA/NA-241).

  4. Environmental monitoring for detection of uranium enrichment operations: Comparison of LEU and HEU facilities

    SciTech Connect (OSTI)

    Hembree, D.M. Jr.; Carter, J.A.; Ross, H.H.

    1995-03-01T23:59:59.000Z

    In 1994, the International Atomic Energy Agency (IAEA) initiated an ambitious program of worldwide field trials to evaluate the utility of environmental monitoring for safeguards. Part of this program involved two extensive United States field trials conducted at the large uranium enrichment facilities. The Paducah operation involves a large low-enriched uranium (LEU) gaseous diffusion plant while the Portsmouth facilities include a large gaseous diffusion plant that has produced both LEU and high-enriched uranium (HEU) as well as an LEU centrifuge facility. As a result of the Energy Policy Act of 1992, management of the uranium enrichment operations was assumed by the US Enrichment Corporation (USEC). The facilities are operated under contract by Martin Marietta Utility Services. Martin Marietta Energy Systems manages the environmental restoration and waste management programs at Portsmouth and Paducah for DOE. These field trials were conducted. Samples included swipes from inside and outside process buildings, vegetation and soil samples taken from locations up to 8 km from main sites, and hydrologic samples taken on the sites and at varying distances from the sites. Analytical results from bulk analysis were obtained using high abundance sensitivity thermal ionization mm spectrometers (TIMS). Uranium isotopics altered from the normal background percentages were found for all the sample types listed above, even on vegetation 5 km from one of the enrichment facilities. The results from these field trials demonstrate that dilution by natural background uranium does not remove from environmental samples the distinctive signatures that are characteristic of enrichment operations. Data from swipe samples taken within the enrichment facilities were particularly revealing. Particulate analysis of these swipes provided a detailed ``history`` of both facilities, including the assays of the end product and tails for both facilities.

  5. Fissile Flow and Enrichment Monitor for GCEP Advanced Safeguards Application

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

    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.

  6. Relocation and repair of the National Geotechnical Centrifuge. Final report

    SciTech Connect (OSTI)

    Cheney, J.A. [California Univ., Davis, CA (United States). Center for Geotechnical Modeling

    1994-10-01T23:59:59.000Z

    In January of 1984, the large geotechnical centrifuge located at NASA Ames Research Center, was in the first stages of operational checkout when the main thrust bearing of the large D.C. drive motor failed. After many months of investigation and proposals for repair of the facility, it became evident that it would be far more advantageous to the engineering community to remove those components of the centrifuge that were undamaged to the Davis campus and replace the drive system completely. The large centrifuge had cost over 2 million dollars to build, and it would have been irresponsible to simply scrap it. Recognizing this fact, funds were solicited and received from various sources, and Beam Engineering Inc. was contracted to design and construct the centrifuge at its new location. The University of California contributed a quarter of a million dollars and Tyndall Air Force Base, through Los Alamos National Laboratory, contributed $140,000. There were funds also contributed by LANL, LLNL, US Navy and NSF. The first stage in the phased development of the newly located centrifuge is nearing completion, which prompts the writing of this report. By the time that this report reaches the reader the first runs of the centrifuge will have been completed. The present report describes the present capability of the centrifuge and the plans for upgrading as time goes on. Several pilot studies were carried out. The experiments involved (1) the effects of nearby explosions on buried thin walled containers and (2) the advection and dispersion of toxic waste water through soils.

  7. Enrichment Strategies Rodents in the Laboratory

    E-Print Network [OSTI]

    Bandettini, Peter A.

    Enrichment Strategies for Rodents in the Laboratory Endorsed by ARAC - 9/8/04 #12 of environmental enrichment on laboratory rats and mice. The development of enrichment programs for non the scientific community. A proactive, systematic, and consistent approach addressing enrichment programs for all

  8. Rules governing the classification of coal slurries for filtering centrifuges

    SciTech Connect (OSTI)

    G.Y. Gol'berg; Y.B. Rubinshtein; S.A. Osadchii [Institute for Enrichment of Solid Fuel (IOTT), Moscow Oblast (Russian Federation)

    2008-07-01T23:59:59.000Z

    The feasibility of using filtering centrifuges for the cleaning of a coking-coal slurry is confirmed in principle, and regime operating parameters which ensure the production of a concentrate of conditioned quality are determined on the basis of results of experimental-industrial tests of a new procedure for this operation at the Neryungrinskaya Concentrating Mill. An equation is proposed for determination of solid carry-off in the centrifuge effluent, which completely satisfactorily (with a correlation coefficient of 0.7-0.8) describes the dependence of the parameter in question on the solid content in the centrifuge feed, and on its content of -0.2-mm material. It is noted that special investigations to determine the effect of the speed of the rotor and shape of the particles on the amount of solid carry-off in the centrifuge effluent are required for construction of a model describing the size reduction of solid-phase particles in the effluent during centrifuge filtration.

  9. A fuzzy controlled three-phase centrifuge for waste separation

    SciTech Connect (OSTI)

    Parkinson, W.J.; Smith, R.E. [Los Alamos National Lab., NM (United States); Miller, N. [Centech, Inc., Casper, WY (United States)

    1998-02-01T23:59:59.000Z

    The three-phase centrifuge technology discussed in this paper was developed by Neal Miller, president of Centech, Inc. The three-phase centrifuge is an excellent device for cleaning up oil field and refinery wastes which are typically composed of hydrocarbons, water, and solids. The technology is unique. It turns the waste into salable oil, reusable water, and landfill-able solids. No secondary waste is produced. The problem is that only the inventor can set up and run the equipment well enough to provide an optimal cleanup. Demand for this device has far exceeded a one man operation. There is now a need for several centrifuges to be operated at different locations at the same time. This has produced a demand for an intelligent control system, one that could replace a highly skilled operator, or at least supplement the skills of a less experienced operator. The control problem is ideally suited to fuzzy logic, since the centrifuge is a highly complicated machine operated entirely by the skill and experience of the operator. A fuzzy control system was designed for and used with the centrifuge.

  10. Centrifugal force reversal from the perspective of rigidly rotating observer

    E-Print Network [OSTI]

    Giorgi Dalakishvili

    2011-12-26T23:59:59.000Z

    In previous studies the dynamics of the relativistic particle moving along the rotating pipe was investigated. The simple gedanken experiment was considered. It was shown that at large enough velocities a centrifugal force acting on the bead changes its usual sign and attracts towards the rotation axis. The authors studied motion of the particle along the rotating straight pipe in the frame of the observer located in the center of rotation, also dynamics of centrifugally accelerated relativistic particle was studied in the laboratory frame. In the both cases it was shown that centrifugal force changes sign. Recently the problem was studied in the frame of stationary observers. It was argued that centrifugal acceleration reversal is not frame invariant effect. In the present paper we consider motion of particle along the rotating straight line in the frame of an arbitrary stationary observer located at certain distance form the center of rotation and rigidly rotating with constant angular velocity. It is shown that any stationary observer could detect reversal of centrifugal acceleration.

  11. Observational Tests of Intergalactic Enrichment Models

    E-Print Network [OSTI]

    Anthony Aguirre; Joop Schaye

    2005-04-19T23:59:59.000Z

    We summarize recent results assessing the carbon and silicon abundances of the intergalactic medium (IGM) using the `pixel optical depth' technique. We briefly discuss the implications of these results for models of intergalactic enrichment, focusing on distinguishing `early' z >> 4 enrichment by the first generations of stars and objects from `late' enrichment by 2 enrichment, and draw qualitative implications for the general picture of intergalactic enrichment at z > 2.

  12. Enrichment of light hydrocarbon mixture

    DOE Patents [OSTI]

    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)

    2010-08-10T23:59:59.000Z

    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.

  13. Enrichment of light hydrocarbon mixture

    DOE Patents [OSTI]

    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)

    2011-11-29T23:59:59.000Z

    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.

  14. Centrifugal cosmological repulsive force in a homogeneous universe

    E-Print Network [OSTI]

    A. V. Klimenko; V. A. Klimenko

    2011-03-21T23:59:59.000Z

    We study the dynamics of homogeneous isotropic three-dimensional worlds filled with radiation (3R-worlds). It is shown that the dynamics of these worlds with the additional fourth large-scale spatial dimension leads to an important effect. At 3R-worlds the forces of repulsion appear. The source of these forces is the thermal energy of the radiation that fills these worlds. In the four-dimensional space, these forces are centrifugal. They operate in an external for 3R-world spatial dimension and stretch it. In the three-dimensional comoving coordinate system the centrifugal forces shows themselves as forces of repulsion. Standard Einstein's equations do not describe these forces. Written generalized Einstein's equation describing the dynamics of a homogeneous isotropic universe, taking into consideration the centrifugal forces of repulsion. We propose a cosmological model of the universe, based on these equations. This model apply to explain the observation data.

  15. Centrifuge Techniques and Apparatus for Transport Experiments in Porous Media

    SciTech Connect (OSTI)

    Earl D. Mattson; Carl D. Paler; Robert W. Smith; Markus Flury

    2010-06-01T23:59:59.000Z

    This paper describes experimental approaches and apparatus that we have developed to study solute and colloid transport in porous media using Idaho National Laboratory's 2-m radius centrifuge. The ex-perimental techniques include water flux scaling with applied acceleration at the top of the column and sub-atmospheric pressure control at the column base, automation of data collection, and remote experimental con-trol over the internet. These apparatus include a constant displacement piston pump, a custom designed liquid fraction collector based on switching valve technology, and modified moisture monitoring equipment. Suc-cessful development of these experimental techniques and equipment is illustrated through application to transport of a conservative tracer through unsaturated sand column, with centrifugal acceleration up to 40 gs. Development of such experimental equipment that can withstand high accelerations enhances the centrifuge technique to conduct highly controlled unsaturated solute/colloid transport experiments and allows in-flight liquid sample collection of the effluent.

  16. Performance improvement of Gas-Liquid Cylindrical Cyclone separator using different design for tangential inlet

    E-Print Network [OSTI]

    Barbuceanu, Nicolae

    2001-01-01T23:59:59.000Z

    separators often rely on centrifugal forces to enhance the separation process and are therefore highly dependent on inlet geometry. This paper investigates expanding the operational envelope of a compact Gas-Liquid Cylindrical Cyclone separator through...

  17. Magneto-Centrifugal Launching of Jets from Accretion Disks. I: Cold Axisymmetric Flows

    E-Print Network [OSTI]

    R. Krasnopolsky; Z. -Y. Li; R. D. Blandford

    1999-07-29T23:59:59.000Z

    The magneto-centrifugal model for jet formation is studied by time-dependent simulations reaching steady state in a cold gas with negligible fluid pressure, in an axisymmetric geometry, using a modification of the Zeus3D code adapted to parallel computers. The number of boundary conditions imposed at the coronal base takes into account the existence of the fast and Alfvenic critical surfaces, avoiding over-determination of the flow. The size and shape of the computational box is chosen to include these critical surfaces, reducing the influence of the outer boundary conditions. As there is a region, near the origin, where the inclination of field lines to the axis is too small to drive a centrifugal wind, we inject a thin, axial jet, expected to form electromagnetically near black holes. Acceleration and collimation appear for wide generic conditions. A reference run is shown in detail, with a wind leaving the computational volume in the axial direction with a poloidal velocity equal to 4 times the poloidal Alfven speed, collimated inside 11 degrees. Finally, the critical surfaces, fieldlines, thrust, energy, torque and mass discharge of the outgoing wind are shown for simulations with various profiles of mass and magnetic flux at the base of the corona.

  18. Magneto-Centrifugal Launching of Jets from Accretion Disks; 1, Cold Axisymmetric Flows

    E-Print Network [OSTI]

    Krasnopolsky, R; Blandford, R D

    1999-01-01T23:59:59.000Z

    The magneto-centrifugal model for jet formation is studied by time-dependent simulations reaching steady state in a cold gas with negligible fluid pressure, in an axisymmetric geometry, using a modification of the Zeus3D code adapted to parallel computers. The number of boundary conditions imposed at the coronal base takes into account the existence of the fast and Alfvenic critical surfaces, avoiding over-determination of the flow. The size and shape of the computational box is chosen to include these critical surfaces, reducing the influence of the outer boundary conditions. As there is a region, near the origin, where the inclination of field lines to the axis is too small to drive a centrifugal wind, we inject a thin, axial jet, expected to form electromagnetically near black holes. Acceleration and collimation appear for wide generic conditions. A reference run is shown in detail, with a wind leaving the computational volume in the axial direction with a poloidal velocity equal to 4 times the poloidal Al...

  19. A comparison of centrifuged and noncentrifuged stallion semen

    E-Print Network [OSTI]

    McCall, James Paul

    1969-01-01T23:59:59.000Z

    August 19S9 lrajor Subj. . ct. ' p[r'clology of 1:cp; duction A COMPARISON OF CENTRIFUGED AND NONCENTRIFUGED STALLION SEMEN A Thesis by JAMES P. McCALL, JR. Approved as to style and content by: (Chairman of Committee) (Head of Department) ember...) / (Member August 1969 ABSTRACT A Comparison. of Centrifuged and Noncentrifuged Stallion Semen. (August 1969) James P. NcCall, Jr. , B. S. Texas A&1'! University Directed by: Dr. A. i4. Sorensen, Jr. Four ejaculates were taken from each of four...

  20. Investigation of flow in centrifugal impeller with tandem inducer

    E-Print Network [OSTI]

    Nishida, Akira

    1976-01-01T23:59:59.000Z

    in a centrifugal impeller w1th a mod1fied tandem inducer have been carried out, with a view to ga1n a poss1ble reduct1on of flow separat1on in the impeller. The compressor characteristics are obtained with the inducer sect1on rotated relative...'IVESTIGATION. Apparatus. Instrumentation. CHAPTER 4 DISCUSSION OF RESULTS 1V V11 1X 8 8 12 18 18 23 25 CHAPTER 5 CONCLUSIONS REFERENCES APPENDIX A QUASI-THREE-DIMENSIONAL POTENTIAL FLOW SOLUTION IN A CENTRIFUGAL COMPRESSOR APPENDIX B BOUNDARY...

  1. Secondary Containment Design for a High Speed Centrifuge

    SciTech Connect (OSTI)

    Snyder, K.W.

    1999-03-01T23:59:59.000Z

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  2. Numerical simulation of the impeller tip clearance effect on centrifugal compressor performance

    E-Print Network [OSTI]

    Hoenninger, Corbett Reed

    2001-01-01T23:59:59.000Z

    This thesis presents the numerical simulation of flow in centrifugal compressors. A three-dimensional Navier-Stokes solver was employed to simulate flow through two centrifugal compressors. The first compressor simulated was the NASA low speed...

  3. Scales modified for use on board the human centrifuge in the MIT Man Vehicle Lab

    E-Print Network [OSTI]

    Samuelson, Heather Marie

    2006-01-01T23:59:59.000Z

    The MIT Man Vehicle Lab (MVL) is currently performing research on the effects of rotational artificial gravity on humans through the use of a short-radius centrifuge. The MVL centrifuge allows subjects to spin in the supine ...

  4. Cushioned centrifugation of stallion semen: factors impacting equine sperm recovery rate and quality

    E-Print Network [OSTI]

    Waite, Jessica Arlene

    2009-05-15T23:59:59.000Z

    Centrifugation of stallion semen is an integral part of the cryopreservation procedure, primarily allowing for the concentration of sperm and removal of seminal plasma. In addition, centrifugation is required for maximizing spermatozoal quality...

  5. Cushioned centrifugation of stallion semen: factors impacting equine sperm recovery rate and quality

    E-Print Network [OSTI]

    Waite, Jessica Arlene

    2008-10-10T23:59:59.000Z

    Centrifugation of stallion semen is an integral part of the cryopreservation procedure, primarily allowing for the concentration of sperm and removal of seminal plasma. In addition, centrifugation is required for maximizing spermatozoal quality...

  6. Effect of Density Gradient Centrifugation on Quality and Recovery Rate of Equine Sperm

    E-Print Network [OSTI]

    Edmond, Ann J.

    2010-07-14T23:59:59.000Z

    gradient volume (height) on stallion sperm quality and recovery rate in sperm pellets following centrifugation. In all three experiments, equine semen was initially centrifuged to increase sperm concentration. In Experiment 1, one-mL aliquots were layered...

  7. Enrichment of the Intergalactic Medium by the Milky Way Subgroup

    E-Print Network [OSTI]

    Leticia Carigi

    2001-08-27T23:59:59.000Z

    I study the effect of the galaxies of the Milky Way subgroup on the chemical enrichment of the diffuse gas within the Local Group. The preferred model predicts that the present-day intergalactic medium mass is 1/22 of the initial baryonic mass and its metallicity is 1/20 $Z_\\odot$. Nearly 80 % of intergalactic metals were produced in the Galactic bulge.

  8. Anisotropic Outflows and IGM Enrichment

    E-Print Network [OSTI]

    Hugo Martel; Matthew M. Pieri; Cedric Grenon

    2006-11-17T23:59:59.000Z

    We have designed an analytical model for the evolution of anisotropic galactic outflows. These outflows follow the path of least resistance, and thus travel preferentially into low-density regions, away from cosmological structures where galaxies form. We show that anisotropic outflows can significantly enrich low-density systems with metals.

  9. Centrifuge Permeameter for Unsaturated Soils. II: Measurement of the Hydraulic Characteristics

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    calculation of K. An infusion pump located outside of the centrifuge and a low-flow rotary joint are used

  10. IEEE Visualization Contest 2011 Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    E-Print Network [OSTI]

    IEEE Visualization Contest 2011 Visualizing Unsteady Vortical Behavior of a Centrifugal Pump number 226042. em eg We present our results analyzing a centrifugal pump as a part of the IEEE Visualization Contest 2011. The given data set represents a high resolution simulation of a centrifugal pump

  11. Centrifuge Permeameter for Unsaturated Soils. I: Theoretical Basis and Experimental Developments

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    Centrifuge Permeameter for Unsaturated Soils. I: Theoretical Basis and Experimental Developments Jorge G. Zornberg, M.ASCE1 ; and John S. McCartney, A.M.ASCE2 Abstract: A new centrifuge permeameter the centrifuge permeame- ter for concurrent determination of the soil-water retention curve SWRC and hydraulic

  12. THE CENTRIFUGE PERMEAMETER FOR UNSATURATED SOILS (CPUS) By: John McCartney1

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    THE CENTRIFUGE PERMEAMETER FOR UNSATURATED SOILS (CPUS) By: John McCartney1 and Jorge Zornberg, Advisor2 Abstract: This paper describes the development of a new centrifuge permeameter capable inflow rates (0.1 ml/min) within a rotating centrifuge environment, capable of imposing an acceleration

  13. Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux

    E-Print Network [OSTI]

    Rioux, Frank

    Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux Some quantum textbooks invoke with involves the middle term in the Hamiltonian given above. Some authors call it the centrifugal potential the effective potential energy. In support of this maneuver they invoke the idea of centrifugal force, which

  14. DETERMINATION OF THE SWELL-STRESS CURVE OF AN EXPANSIVE SOIL USING CENTRIFUGE TECHNOLOGY

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    DETERMINATION OF THE SWELL-STRESS CURVE OF AN EXPANSIVE SOIL USING CENTRIFUGE TECHNOLOGY project was conducted on the use of centrifuge technology to characterize the expansive properties of a soil sample in the centrifuge. This paper focuses on the analysis of testing results, specifically how

  15. Modeling for surge control of centrifugal compresssors: comparison with experiment

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    con- trol design, of a centrifugal compression system is vali- dated. Compressor surge is an unwanted pressure rise and e¢ciency, and it narrows the operating range of the compressor. Ac- tive surge control is validated. The background for this is the need for a energy based model including the rotational speed

  16. Metal Enrichment of the Intergalactic Medium in Cosmological Simulations

    E-Print Network [OSTI]

    Anthony Aguirre; Lars Hernquist; Joop Schaye; Neal Katz; David H. Weinberg; Jeffrey Gardner

    2001-07-17T23:59:59.000Z

    Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~0.1-1% solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to 1/3-1/2 solar metallicity at z=0. Metals in the IGM may have been removed from galaxies (in which they presumably form) during dynamical encounters between galaxies, by ram-pressure stripping, by supernova-driven winds, or as radiation-pressure driven dust efflux. This study develops a method of investigating the chemical enrichment of the IGM and of galaxies, using already completed cosmological simulations. To these simulations, we add dust and (gaseous) metals, distributing the dust and metals in the gas according to three simple parameterized prescriptions, one for each enrichment mechanism. These prescriptions are formulated to capture the basic ejection physics, and calibrated when possible with empirical data. Our results indicate that dynamical removal of metals from >~ 3*10^8 solar mass galaxies cannot account for the observed metallicity of low-column density Ly-alpha absorbers, and that dynamical removal from >~ 3*10^10 solar mass galaxies cannot account for the ICM metallicities. Dynamical removal also fails to produce a strong enough mass-metallicity relation in galaxies. In contrast, either wind or radiation-pressure ejection of metals from relatively large galaxies can plausibly account for all three sets of observations (though it is unclear whether metals can be distributed uniformly enough in the low-density regions without overly disturbing the IGM, and whether clusters can be enriched quite as much as observed). We investigate in detail how our results change with variations in our assumed parameters, and how results for the different ejection processes compare. (Abridged)

  17. Screen bowl centrifuge: a high-efficiency particle size separator

    SciTech Connect (OSTI)

    Mohanty, M.K.; Zhang, B.; Khanna, N.; Palit, A.; Dube, B. [South Illinois University, Carbondale, IL (United States). Dept. for Mining & Mineral Resources Engineering

    2008-05-15T23:59:59.000Z

    Over the years, screen bowl centrifuges have been widely used for dewatering fine coal in coal preparation plants in the United States and elsewhere. It is generally recognized in the engineering and scientific communities that screen bowl centrifuges provide some degree of particle size separation while dewatering fine coal in a common application. However, the extent of differential partitioning of coarse and fine particles achievable by a screen bowl centrifuge has not been systematically studied in the past. The present investigation was aimed at conducting a parametric study using a statistically designed experimental program to better understand and optimize the size classification performance of a screen bowl centrifuge. A continuously operating screen bowl centrifuge having a bowl diameter of 0.5 m was used for this study at the Illinois Coal Development Park. Three key operating parameters, i.e., feed flow rate, feed solid content and pool depth, were varied to conduct a total of 17 experiments using a three-level factorial test matrix. Some of the best size separation performances achieved in this study may be described as having an imperfection value of 0.13 at an effective separation size (d(50c)) of 38 mu m and an imperfection value of 0.27 at an effective separation size (d(50c)) of 2.8 mu m. Due to an effective separation of ultrafine high ash materials, the ash content of the screen bowl feed was reduced from 22.3% to a minimum of 8.84% with a combustible recovery of 84.1% and an ash rejection of 71.6%. A higher combustible recovery of 92.1% was achieved at a product ash content of 12.5% with a d(50c) of 2.8 mu m and imperfection of 0.27.

  18. Stable carbon and nitrogen isotope enrichment in primate tissues

    E-Print Network [OSTI]

    Crowley, Brooke E.; Carter, Melinda L.; Karpanty, Sarah M.; Zihlman, Adrienne L.; Koch, Paul L.; Dominy, Nathaniel J.

    2010-01-01T23:59:59.000Z

    carbon and nitrogen isotope enrichment in primate tissuesfactor (a) and isotope enrichment values (e), which provideisotope values from different modern primate tissues. Additionally, using these mean apparent enrichment

  19. Stable carbon and nitrogen isotope enrichment in primate tissues

    E-Print Network [OSTI]

    Crowley, Brooke E.; Carter, Melinda L.; Karpanty, Sarah M.; Zihlman, Adrienne L.; Koch, Paul L.; Dominy, Nathaniel J.

    2010-01-01T23:59:59.000Z

    and nitrogen isotope enrichment in primate tissues Brooke E.and nitrogen apparent enrichment (e*) values ± one standardexplored the apparent enrichment (e*) between bone collagen

  20. Augmented Shelf: Digital Enrichment of Library Shelves

    E-Print Network [OSTI]

    Reiterer, Harald

    Augmented Shelf: Digital Enrichment of Library Shelves Eike Kleiner1 , Benjamin Schäfer2;Augmented Shelf: Digital Enrichment of Library Shelves 2 yon 2007) and Augmented Reality (Azuma 1997) a prototype1 was designed which supports users browsing the physical shelves enriched with digital functions

  1. SHORT COMMUNICATION Chiral Enrichment of Serine

    E-Print Network [OSTI]

    Clemmer, David E.

    SHORT COMMUNICATION Chiral Enrichment of Serine via Formation, Dissociation, and Soft University, Bloomington, Indiana, USA Chiral enrichment of serine is achieved in experiments that involve of chirally-enriched octameric cluster ions and their dissociation, viz. Ser1 3 Ser8 3 Ser1, allows serine

  2. How Did the IGM Become Enriched?

    E-Print Network [OSTI]

    Anthony Aguirre; Joop Schaye

    2006-11-20T23:59:59.000Z

    The enrichment of the intergalactic medium with heavy elements is a process that lies at the nexus of poorly-understood aspects of physical cosmology. We review current understanding of the processes that may remove metals from galaxies, the basic predictions of these models, the key observational constraints on enrichment, and how intergalactic enrichment may be used to test cosmological simulations.

  3. H-D Substitution in Interstellar Solid Methanol: A Key Route for D Enrichment

    E-Print Network [OSTI]

    Akihiro Nagaoka; Naoki Watanabe; Akira Kouchi

    2005-03-28T23:59:59.000Z

    Deuterium enrichment of interstellar methanol is reproduced experimentally for the first time via grain-surface H-D substitution in solid methanol at an atomic D/H ratio of 0.1. Although previous gas-grain models successfully reproduce the deuterium enrichments observed in interstellar methanol molecules (D/H of up to 0.4, compared to the cosmic ratio of $\\sim 10^{-5})$, the models exclusively focus on deuterium fractionation resulting from the successive addition of atomic hydrogen/deuterium on CO. The mechanism proposed here represents a key route for deuterium enrichment that reproduces the high observed abundances of deuterated methanol, including multiple deuterations.

  4. Honors Enrichment Contracts Faculty View Page 1 Honors Enrichment Contracts Faculty View

    E-Print Network [OSTI]

    Honors Enrichment Contracts ­ Faculty View Page 1 Honors Enrichment Contracts ­ Faculty View INITIAL APPROVAL #12;Honors Enrichment Contracts ­ Faculty View Page 2 Summary This document contains information about how to make initial and final decisions on Honors Enrichment Contracts submitted by honors

  5. 2013 Huayu Enrichment Scholarship 1 Educational Division, TECO in Canada

    E-Print Network [OSTI]

    Shoubridge, Eric

    2013 Huayu Enrichment Scholarship 1 Educational Division, TECO in Canada 2013 Huayu Enrichment Scholarship PURPOSE Huayu Enrichment Scholarship is executed in accordance with "Ministry of Education Huayu Enrichment Scholarship (HES) International Student Directions" (see Appendix 1

  6. Practical considerations in realizing a magnetic centrifugal mass filter

    SciTech Connect (OSTI)

    Gueroult, Renaud; Fisch, Nathaniel J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2012-12-15T23:59:59.000Z

    The magnetic centrifugal mass filter concept represents a variation on the plasma centrifuge, with applications that are particularly promising for high-throughput separation of ions with large mass differences. A number of considerations, however, constrain the parameter space in which this device operates best. The rotation speed, magnetic field intensity, and ion temperature are constrained by the ion confinement requirements. Collisions must also be large enough to eject ions, but small enough not to eject them too quickly. The existence of favorable regimes meeting these constraints is demonstrated by a single-particle orbit code. As an example of interest, it is shown that separation factors of about 2.3 are achievable in a single pass when separating Aluminum from Strontium ions.

  7. Adjustable Speed Drives as Applied to Centrifugal Pumps

    E-Print Network [OSTI]

    Jarc, D. A.; Robechek, J. D.; Connors, D. P.

    1982-01-01T23:59:59.000Z

    Required Power In addition to energy savings, which are discussed in detail later, operation at reduced pressures can result in longer pump seal life, reduced impeller wear, and less system vibration and noise. These benefits could provide additional... FLOW CONTROL TECHNIQUES Historically, centrifugal pumps have been driven by fixed speed A-C motors and reduced flow has been achieved by using control valves as shown in Figure 8. Closing the valve reduces the flow by increasing the friction...

  8. Chemical Enrichment at High Redshifts

    E-Print Network [OSTI]

    Snigdha Das; Pushpa Khare

    1998-08-09T23:59:59.000Z

    We have tried to understand the recent observations related to metallicity in Ly $\\alpha$ forest clouds in the framework of the two component model suggested by Chiba & Nath (1997). We find that even if the mini-halos were chemically enriched by an earlier generation of stars, to have [C/H] $\\simeq$ -2.5, the number of C IV lines with column density $>10^{12} cm^{-2}$, contributed by the mini-halos, at the redshift of 3, would be only about 10% of the total number of lines, for a chemical enrichment rate of $(1+z)^{-3}$ in the galaxies. Recently reported absence of heavy element lines associated with most of the Ly $\\alpha$ lines with H I column density between $10^{13.5} cm^{-2}$ and $10^{14} cm^{-2}$ by Lu et al (1998), if correct, gives an upper limit on [C/H]=-3.7, not only in the mini-halos, but also in the outer parts of galactic halos. This is consistent with the results of numerical simulations, according to which, the chemical elements associated with the Ly $\\alpha$ clouds are formed in situ in clouds, rather than in an earlier generation of stars. However, the mean value of $7 \\times 10^{-3}$ for the column density ratio of C IV and H I, determined by Cowie and Songaila (1998) for low Lyman alpha optical depths, implies an abundance of [C/H] =-2.5 in mini-halos as well as in most of the region in galactic halos, presumably enriched by an earlier generation of stars. The redshift and column density distribution of C IV has been shown to be in reasonable agreement with the observations.

  9. Removal of impurities from dry scrubbed fluoride enriched alumina

    SciTech Connect (OSTI)

    Schuh, L. [ABB Corporate Research Center, Heidelberg (Germany); Wedde, G. [ABB Environmental, Oslo (Norway)

    1996-10-01T23:59:59.000Z

    The pot-gas from an aluminum electrolytic cell is cleaned by a dry scrubbing process using fresh alumina as a scrubbing agent. This alumina is enriched with fluorides and trace impurities in a closed loop system with the pots. The only significant removal of the impurities is due to metal tapping. An improved technique has been developed that is more effective than earlier stripper systems. The impurity-rich fine fraction (< 10 {micro}m) of the enriched alumina is partly attached to the coarser alumina. That attachment has to be broken. Selective impact milling under special moderate conditions and air classifying have shown to be a cost effective process for the removal of impurities. For iron (Fe) and phosphorus (P) about 30--70% can be removed by the separation of 0.5--1% of the alumina. Full scale tests have successfully confirmed these results.

  10. On reversal of centrifugal acceleration in special relativity

    E-Print Network [OSTI]

    Maxim Lyutikov

    2009-03-05T23:59:59.000Z

    The basic principles of General Theory of Relativity historically have been tested in gedanken experiments in rotating frame of references. One of the key issues, which still evokes a lot of controversy, is the centrifugal acceleration. Machabeli & Rogava (1994) argued that centrifugal acceleration reverse direction for particles moving radially with relativistic velocities within a "bead on a wire" approximation. We show that this result is frame-dependent and reflects a special relativistic dilution of time (as correctly argued by de Felice (1995)) and is analogous to freezing of motion on the black hole horizon as seen by a remote observer. It is a reversal of coordinate acceleration; there is no such effect as measured by a defined set of observers, e.g., proper and/or comoving. Frame-independent velocity of a "bead" with respect to stationary rotating observers increases and formally reaches the speed of light on the light cylinder. In general relativity, centrifugal force does reverse its direction at photon circular orbit, r=3M in Schwarzschild metric, as argued by Abramowicz (1990).

  11. Stochastic chemical enrichment in metal-poor systems I. Theory

    E-Print Network [OSTI]

    T. Karlsson

    2005-04-27T23:59:59.000Z

    A stochastic model of the chemical enrichment of metal-poor systems by core-collapse (Type II) supernovae is presented, allowing for large-scale mixing of the enriched material by turbulent motions and cloud collisions in the interstellar medium. Infall of pristine material is taken into account by following the evolution of the gas density in the medium. Analytical expressions were derived for the number of stars enriched by a given number of supernovae, as well as for the amount of mass with which the ejected material from a supernova is mixed before being locked up in a subsequently formed star. It is shown that for reasonable values of the gas density (~0.1 cm-3) and of the supernova rate (~0.25 kpc-3 Myr-1) of the Galactic halo, the resulting metallicity distributions of the extreme Population II stars show a distinct cut-off at [Fe/H] ~= -4. In fact, by assuming no low-mass Population III stars were able to form out of the primordial interstellar medium, the derived fraction of stars below [Fe/H] = -4 is in agreement with observations. Moreover, the probability is high that even the most metal-poor stars observed to date have been enriched by several contributing supernovae. This partly explains the relatively small star-to-star scatter in many chemical-abundance ratios for stars down to [Fe/H] = -4, as recently found in several observational studies. Contribution from the thermonuclear (Type Ia) supernovae is found to be negligible over almost the entire extremely metal-poor regime. (***abridged***)

  12. EFFECT OF DUST ENRICHMENT ON SOLID AND LIQUID COMPOSITIONS IN EQUILIBRIUM WITH COSMIC GASES. D.S. Ebel1 and and L. Grossman1,2, 1Department of the Geophysical Sciences, 5734 South Ellis Ave.,

    E-Print Network [OSTI]

    Grossman, Lawrence

    EFFECT OF DUST ENRICHMENT ON SOLID AND LIQUID COMPOSITIONS IN EQUILIBRIUM WITH COSMIC GASES. D is that chondrule liquids formed by direct condensa- tion from nebular gas enriched in precondensed dust [4]. Both is enrichment in precon- densed dust [10, 11]. We have mapped equilibrium com- positions of liquid

  13. Metal Enrichment of the Intergalactic Medium at z=3 by Galactic Winds

    E-Print Network [OSTI]

    Anthony Aguirre; Lars Hernquist; Joop Schaye; David Weinberg; Neal Katz; Jeffrey Gardner

    2001-06-08T23:59:59.000Z

    Studies of quasar absorption lines reveal that the low density intergalactic medium at z ~ 3 is enriched to 0.001-0.01 solar metallicity. This enrichment may have occurred in an early generation of Population III stars at redshift z >~ 10, by protogalaxies at 6 enrichment of the IGM at z >~ 3 by galaxies of baryonic mass >~ 10^8.5 solar masses. We use already completed cosmological simulations to which we add a prescription for chemical evolution and metal ejection by winds, assuming that the winds have properties similar to those observed in local starbursts and Lyman-break galaxies. Results are given for a number of representative models, and we also examine the properties of the galaxies responsible for the enrichment as well as the physical effects responsible for wind escape and propagation. We find that winds of velocity >~ 200-300 km/s are capable of enriching the IGM to the mean level observed, though many low-density regions would remain metal free. Calibrated by observations of Lyman-break galaxies, our calculations suggest that most galaxies at z >~ 3 should drive winds that can escape and propagate to large radii. The primary effect limiting the enrichment of low-density IG gas in our scenario is then the travel time from high- to low-density regions, implying that the metallicity of low-density gas is a strong function of redshift.

  14. Centrifugal accelerator, system and method for removing unwanted layers from a surface

    DOE Patents [OSTI]

    Foster, Christopher A. (Clinton, TN); Fisher, Paul W. (Heiskell, TN)

    1995-01-01T23:59:59.000Z

    A cryoblasting process having a centrifugal accelerator for accelerating frozen pellets of argon or carbon dioxide toward a target area utilizes an accelerator throw wheel designed to induce, during operation, the creation of a low-friction gas bearing within internal passages of the wheel which would otherwise retard acceleration of the pellets as they move through the passages. An associated system and method for removing paint from a surface with cryoblasting techniques involves the treating, such as a preheating, of the painted surface to soften the paint prior to the impacting of frozen pellets thereagainst to increase the rate of paint removal. A system and method for producing large quantities of frozen pellets from a liquid material, such as liquid argon or carbon dioxide, for use in a cryoblasting process utilizes a chamber into which the liquid material is introduced in the form of a jet which disintegrates into droplets. A non-condensible gas, such as inert helium or air, is injected into the chamber at a controlled rate so that the droplets freeze into bodies of relatively high density.

  15. Towards development of an incipient surge detection device for centrifugal compressors 

    E-Print Network [OSTI]

    Hassinger, David Alan

    1978-01-01T23:59:59.000Z

    OF FIGURES Page 10 12 13 14 Typical Compressor Performance Nap. Centrifugal Compressor Components. Variation of Lift Coefficient due to Changing Angle of Incidence. Inducer Blade Stall. Common Centrifugal Compressor Diffusers Diffuser Vane Stall... within the boundary-layer in the centrifugal compressor diffuser throat. The design of the device will now be expanded upon. Design of Boundary-layer Probe In order to measure the flow within the boundary-layer of the diffuser, a boundary-layer probe...

  16. Stresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Stresa, Italy, 26-28 April 2006 A SILICON-BASED MICRO GAS TURBINE ENGINE FOR POWER GENERATION X. C. Our research aims to develop a micro power generation systems based on micro gas turbine engine and a piezoelectric converter, as illustrated in Fig. 1 [6]. The micro gas turbine engine is composed of a centrifugal

  17. Separation of gases through gas enrichment membrane composites

    DOE Patents [OSTI]

    Swedo, R.J.; Kurek, P.R.

    1988-07-19T23:59:59.000Z

    Thin film composite membranes having as a permselective layer a film of a homopolymer of certain vinyl alkyl ethers are useful in the separation of various gases. Such homopolymers have a molecular weight of greater than 30,000 and the alkyl group of the vinyl alkyl monomer has from 4 to 20 carbon atoms with branching within the alkyl moiety at least at the carbon atom bonded to the ether oxygen or at the next adjacent carbon atom. These membranes show excellent hydrolytic stability, especially in the presence of acidic or basic gaseous components.

  18. Separation of gases through gas enrichment membrane composites

    DOE Patents [OSTI]

    Swedo, Raymond J. (Mt. Prospect, IL); Kurek, Paul R. (Schaumburg, IL)

    1988-01-01T23:59:59.000Z

    Thin film composite membranes having as a permselective layer a film of a homopolymer of certain vinyl alkyl ethers are useful in the separation of various gases. Such homopolymers have a molecular weight of greater than 30,000 and the alkyl group of the vinyl alkyl monomer has from 4 to 20 carbon atoms with branching within the alkyl moiety at least at the carbon atom bonded to the ether oxygen or at the next adjacent carbon atom. These membranes show excellent hydrolytic stability, especially in the presence of acidic or basic gaseous components.

  19. On the enrichment of the intergalactic medium by galactic winds

    E-Print Network [OSTI]

    Biman Nath; Neil Trentham

    1997-07-16T23:59:59.000Z

    Observations of metal lines in $\\lyal$ absorption systems of small H~I column density and their ubiquitous nature suggest that the intergalactic medium (IGM) was enriched to about $Z \\sim 0.01 \\> Z_{\\odot}$ by a redshift $z \\sim 3$. We investigate the role of winds from small star-forming galaxies at high $z$ in enriching the IGM. The existence of large numbers of small galaxies at high $z$ follows naturally from hierarchical clustering theories (e.g. CDM). For analytical simplicity we assume that the galactic winds escape the galaxies at a single characteristic redshift $z_{in}$, and we model the galactic winds as spherical shock waves propagating through the IGM. We then calculate the probability distribution of the metallicity of the IGM, as a function of time (for different values of $z_{in}$), adopting plausible galaxy mass functions (from Press-Schechter formalism), cooling physics, star-formation efficiencies, gas ejection dynamics, and nucleosynthesis yields. We compare this expected distribution with the observed distribution of metallicities in the Ly$\\alpha$ forest at $z=3$, the metal poor stars in the halo of our Galaxy, and with other observational constraints on such a scenario. We find that galactic winds at high $z$ could have enriched the IGM to a mean metallicity of $Z \\sim 0.01 Z_{\\odot}$ at $z \\sim 3$, with a standard deviation of the same order, if $z_{in} \\la 5$, and that this satisfies all the observational constraints.

  20. The chemical enrichment of the ICM from hydrodynamical simulations

    E-Print Network [OSTI]

    S. Borgani; D. Fabjan; L. Tornatore; S. Schindler; K. Dolag; A. Diaferio

    2008-01-07T23:59:59.000Z

    The study of the metal enrichment of the intra-cluster and inter-galactic media (ICM and IGM) represents a direct means to reconstruct the past history of star formation, the role of feedback processes and the gas-dynamical processes which determine the evolution of the cosmic baryons. In this paper we review the approaches that have been followed so far to model the enrichment of the ICM in a cosmological context. While our presentation will be focused on the role played by hydrodynamical simulations, we will also discuss other approaches based on semi-analytical models of galaxy formation, also critically discussing pros and cons of the different methods. We will first review the concept of the model of chemical evolution to be implemented in any chemo-dynamical description. We will emphasise how the predictions of this model critically depend on the choice of the stellar initial mass function, on the stellar life-times and on the stellar yields. We will then overview the comparisons presented so far between X-ray observations of the ICM enrichment and model predictions. We will show how the most recent chemo-dynamical models are able to capture the basic features of the observed metal content of the ICM and its evolution. We will conclude by highlighting the open questions in this study and the direction of improvements for cosmological chemo-dynamical models of the next generation.

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

    E-Print Network [OSTI]

    Danica Kröger; Gerhard Hensler; Tim Freyer

    2006-03-08T23:59:59.000Z

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

  2. Centrifugal-Barrier Effects and Determination of the Interaction Radius

    E-Print Network [OSTI]

    Ning Wu

    2013-05-21T23:59:59.000Z

    The interaction radius of a resonance is an important physical quantity to describe the structure of a resonance. But, for a long time, physicists do not find a reliable way to measure the magnitude of the interaction radius of a resonance. In this paper, a method is proposed to measure the interaction radius in physics analysis. It is found that the centrifugal barrier effects have great influence to physical results obtained in the PWA fit, and the interaction radius of some resonances can be well measured in the fit.

  3. EIS-0468: American Centrifuge Plant, Piketon, Ohio | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised FindingDepartmentDepartment of Energy Notice8: American Centrifuge68:

  4. Final Environmental Impact Statement for the construction and operation of Claiborne Enrichment Center, Homer, Louisiana (Docket No. 70-3070)

    SciTech Connect (OSTI)

    Zeitoun, A. [Science Applications International Corp., Germantown, MD (United States)

    1994-08-01T23:59:59.000Z

    This two-volume Final Environmental Impact Statement (FEIS) was prepared by the Nuclear Regulatory Commission (NRC) in accordance with regulation 10 CFR Part 51, which implements the National Environmental Policy Act (NEPA). Volume 1 contains the assessment of the potential environmental impacts for licensing the construction and operation of a proposed gaseous centrifuge enrichment facility to be built in Claiborne Parish, Louisiana, by Louisiana Energy Services, LP. (LES). The proposed facility would have a production capacity of about 866 metric tons annually of up to 5 weight percent enriched UF{sub 6}, using a proven centrifuge technology. Included in the assessment are construction, both normal operations and potential accidents (internal and external events), and the eventual decontamination and decommissioning (D&D)- of the site. Issues addressed include the purpose and need for the facility, the alternatives to the proposed action, potential disposition of the tails, the site selection process, and environmental justice. The NRC staff concludes that the facility can be constructed and operated with small and acceptable impacts on the public and the environment. The FEIS supports issuance of a license to the applicant, Louisiana Energy Services, to authorize construction and operation of the proposed facility.

  5. PII S0016-7037(99)00284-7 Condensation in dust-enriched systems

    E-Print Network [OSTI]

    Grossman, Lawrence

    of the resulting condensates. The computations included 23 elements and 374 gas species, and were done over a rangePII S0016-7037(99)00284-7 Condensation in dust-enriched systems DENTON S. EBEL 1 and LAWRENCE--Full equilibrium calculations of the sequence of condensation of the elements from cosmic gases made by total

  6. Shared Investment by NIS and National Labs Develops Cutting-Edge Safeguards Technologies

    SciTech Connect (OSTI)

    Anheier, Norman C.; Williams, Laura S.

    2012-04-01T23:59:59.000Z

    This article, regarding a new technology for detecting undeclared enrichment at gas centrifuge enrichment plants, was written for the DOE/NNSA NA-24 Highlights, a newsletter intended for public release.

  7. Centrifuge study of DNAPL transport in granular media

    SciTech Connect (OSTI)

    Pantazidou, M.; Abu-Hassanein, Z.S.; Riemer, M.F.

    2000-02-01T23:59:59.000Z

    The migration potential of dense nonaqueous phase liquids (DNAPLs) in saturated soil was investigated experimentally using the elevated acceleration field of the geotechnical centrifuge. The transport of the DNAPL was monitored with a video camera in flight, through the transparent wall of the sample box. By using measurements of the velocity of the DNAPL front from models corresponding to the same prototype and applying the technique of modeling of models, the stable infiltration of a low density, high viscosity DNAPL in saturated homogeneous media was shown to scale properly in the centrifuge. The visual observations confirmed the correlations between the DNAPL physicochemical properties and transport patterns, which have important consequences for the characterization of DNAPL-contaminated sites. Infiltrating DNAPLs of high density and low viscosity displace water in an unstable manner and create extensive contaminated areas characterized by non-uniform DNAPL distributions. In contrast, the displacement of water by DNAPLs of low density and high viscosity is stable and efficient, and hence, results in smaller contaminated areas of high DNAPL saturation. Numerical simulations yielded predictions and sensitivity analysis results that agreed well with these experimental observations.

  8. Centrifugal compression of soft particle packings - theory and experiment

    E-Print Network [OSTI]

    K. N. Nordstrom; E. Verneuil; W. G. Ellenbroek; T. C. Lubensky; J. P. Gollub; D. J. Durian

    2010-09-15T23:59:59.000Z

    An exact method is developed for computing the height of an elastic medium subjected to centrifugal compression, for arbitrary constitutive relation between stress and strain. Example solutions are obtained for power-law media and for cases where the stress diverges at a critical strain -- for example as required by packings composed of deformable but incompressible particles. Experimental data are presented for the centrifugal compression of thermo-responsive N-isopropylacrylamide (NIPA) microgel beads in water. For small radial acceleration, the results are consistent with Hertzian elasticity, and are analyzed in terms of the Young elastic modulus of the bead material. For large radial acceleration, the sample compression asymptotes to a value corresponding to a space-filling particle volume fraction of unity. Therefore we conclude that the gel beads are incompressible, and deform without deswelling. In addition, we find that the Young elastic modulus of the particulate gel material scales with cross-link density raised to the power 3.3+-0.8, somewhat larger than the Flory expectation.

  9. Phase-separation of miscible liquids in a centrifuge

    E-Print Network [OSTI]

    Yoav Tsori; Ludwik Leibler

    2007-12-18T23:59:59.000Z

    We show that a liquid mixture in the thermodynamically stable homogeneous phase can undergo a phase-separation transition when rotated at sufficiently high frequency $\\omega$. This phase-transition is different from the usual case where two liquids are immiscible or where the slow sedimentation process of one component (e.g. a polymer) is accelerated due to centrifugation. For a binary mixture, the main coupling is due to a term $\\propto \\Delta\\rho(\\omega r)^2$, where $\\Delta\\rho$ is the difference between the two liquid densities and $r$ the distance from the rotation axis. Below the critical temperature there is a critical rotation frequency $\\omega_c$, below which smooth density gradients occur. When $\\omega>\\omega_c$, we find a sharp interface between the low density liquid close to the center of the centrifuge and a high density liquid far from the center. These findings may be relevant to various separation processes and to the control of chemical reactions, in particular their kinetics.

  10. Centrifugal Breakout of Magnetically Confined Line-Driven Stellar Winds

    E-Print Network [OSTI]

    A. ud-Doula; R. H. D. Townsend; S. P. Owocki

    2006-02-15T23:59:59.000Z

    We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star's rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical value), and also a large magnetic confinement parameter, $\\eta_{\\ast} \\equiv B_{\\ast}^2 R_{\\ast}^{2} / \\dot{M} V_{\\infty} = 600$. The magnetic field channels and torques the wind outflow into an equatorial, rigidly rotating disk extending from near the Kepler corotation radius outwards. Even with fine-tuning at lower magnetic confinement, none of the MHD models produce a stable Keplerian disk. Instead, material below the Kepler radius falls back on to the stellar surface, while the strong centrifugal force on material beyond the corotation escape radius stretches the magnetic loops outwards, leading to episodic breakout of mass when the field reconnects. The associated dissipation of magnetic energy heats material to temperatures of nearly $10^{8}$K, high enough to emit hard (several keV) X-rays. Such \\emph{centrifugal mass ejection} represents a novel mechanism for driving magnetic reconnection, and seems a very promising basis for modeling X-ray flares recently observed in rotating magnetic Bp stars like $\\sigma$ Ori E.

  11. Centrifuge modelling of lateral pipeline/soil interaction -- Phase 2

    SciTech Connect (OSTI)

    Paulin, M.J.; Phillips, R. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Centre for Cold Ocean Resources Engineering; Boivin, R. [NOVA Corp., Calgary, Alberta (Canada). NOVA Gas Transmission Limited Division

    1995-12-31T23:59:59.000Z

    An ongoing research program is investigating the load transfer behavior of buried pipelines subjected to lateral soil movement in cohesive soil. Phase 1 of this study, reported to OMAE `92, demonstrated that the centrifuge technique was appropriate for this application in determining the interaction conditions for the lateral loading of pipelines. Limited control of the shear strength masked geometric effects (trench width and burial depth) on the interaction factors and desiccation affected the interpretation of some of the interaction factors. The Phase 2 study investigated the geometric effects of pipeline soil cover, ditch width and also displacement rate. The study included a ``modelling of models`` test to verify the reliability of the centrifuge modelling technique. This paper addresses two issues: (1) The Phase 1 soil strength profiles and interaction factors were reanalyzed based on an improved understanding of the soil conditions at the time of testing; (2) A selection of the Phase 2 results are presented for a 0.95m diameter pipeline subjected to lateral soil movement. The program results are discussed and compared with current pipeline/soil interaction analysis methods.

  12. Student science enrichment training program

    SciTech Connect (OSTI)

    Sandhu, S.S.

    1994-08-01T23:59:59.000Z

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

  13. The Role of Heating and Enrichment in Galaxy Formation

    E-Print Network [OSTI]

    Evan Scannapieco; Tom Broadhurst

    2000-10-11T23:59:59.000Z

    We show that the winds identified with high-redshift low-mass galaxies may strongly affect the formation of stars in more massive galaxies that form later. With 3D realizations of a simple linear growth model we track gas shocking, metal enrichment, and cooling, together with dark halo formation. We show that outflows typically strip baryonic material out of collapsing intermediate mass halos, suppressing star formation. More massive halos can trap the heated gas but collapse late, leading to a broad bimodal redshift distribution, with a larger characteristic mass associated with the lower redshift peak. This scenario accounts for the observed bell-shaped luminosity function of early type galaxies, explains the small number of Milky Way satellite galaxies relative to Cold Dark Matter models predictions, and provides a possible explanation for the lack of metal poor G-dwarfs in the solar neighborhood and the more general lack of low-metallicity stars in massive galaxies relative to ``closed-box'' models of chemical enrichment. Intergalactic medium heating from outflows should produce spectral distortions in the cosmic microwave background that will be measurable with the next generation of experiments.

  14. Passive gas separator and accumulator device

    DOE Patents [OSTI]

    Choe, H.; Fallas, T.T.

    1994-08-02T23:59:59.000Z

    A separation device employing a gas separation filter and swirler vanes for separating gas from a gas-liquid mixture is provided. The cylindrical filter utilizes the principle that surface tension in the pores of the filter prevents gas bubbles from passing through. As a result, the gas collects in the interior region of the filter and coalesces to form larger bubbles in the center of the device. The device is particularly suited for use in microgravity conditions since the swirlers induce a centrifugal force which causes liquid to move from the inner region of the filter, pass the pores, and flow through the outlet of the device while the entrained gas is trapped by the filter. The device includes a cylindrical gas storage screen which is enclosed by the cylindrical gas separation filter. The screen has pores that are larger than those of the filters. The screen prevents larger bubbles that have been formed from reaching and interfering with the pores of the gas separation filter. The device is initially filled with a gas other than that which is to be separated. This technique results in separation of the gas even before gas bubbles are present in the mixture. Initially filling the device with the dissimilar gas and preventing the gas from escaping before operation can be accomplished by sealing the dissimilar gas in the inner region of the separation device with a ruptured disc which can be ruptured when the device is activated for use. 3 figs.

  15. ULTRA-FAINT DWARF GALAXIES AS A TEST OF EARLY ENRICHMENT AND METALLICITY-DEPENDENT STAR FORMATION

    SciTech Connect (OSTI)

    Tassis, Konstantinos [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Gnedin, Nickolay Y. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Kravtsov, Andrey V. [Kavli Institute for Cosmological Physics and Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States)

    2012-01-20T23:59:59.000Z

    The close relation of star formation with molecular gas indicated by observations and assumed in recent models implies that the efficiency with which galaxies convert their gas into stars depends on gas metallicity. This is because abundance of molecular hydrogen is sensitive to abundance of dust, which catalyzes formation of H{sub 2} and helps to shield it from dissociating radiation. In this study, we point out that in the absence of significant pre-enrichment by Population III stars forming out of zero metallicity gas, such H{sub 2}-based star formation is expected to leave an imprint in the form of bi-modality in the metallicity distribution among dwarf galaxies and in the metallicity distribution of stars within individual galaxies. The bi-modality arises because when gas metallicity (and dust abundance) is low, formation of molecular gas is inefficient, the gas consumption timescale is long, and star formation and metal enrichment proceed slowly. When metallicity reaches a critical threshold value star formation and enrichment accelerate, which leads to rapid increase in both stellar mass and metallicity of galaxies. We demonstrate this process both using a simple analytical model and full cosmological simulations. In contrast, the observed metallicity distributions of dwarf galaxies or stars within them are not bi-modal. We argue that this discrepancy points to substantial early stochastic pre-enrichment by Population III stars to levels Z {approx} 10{sup -2} Z{sub Sun} in dense, star-forming regions of early galaxies.

  16. Numerical modeling and experimental validation of uniform microchamber filling in centrifugal microfluidics

    E-Print Network [OSTI]

    Banerjee, Debjyoti

    microfluidics Jonathan Siegrist,*a Mary Amasia,a Navdeep Singh,b Debjyoti Banerjeeb and Marc Madoua Received 1st analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro on centrifugal microfluidic platforms, numerical modeling using the Volume of Fluids method is performed

  17. Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

    E-Print Network [OSTI]

    Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

  18. Method for isotope enrichment by photoinduced chemiionization

    DOE Patents [OSTI]

    Dubrin, James W. (Walnut Creek, CA)

    1985-01-01T23:59:59.000Z

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

  19. The self-enrichment of galactic halo globular clusters : a clue to their formation ?

    E-Print Network [OSTI]

    G. Parmentier; E. Jehin; P. Magain; C. Neuforge; A. Noels; A. A. Thoul

    1999-11-15T23:59:59.000Z

    We present a model of globular cluster self-enrichment. In the protogalaxy, cold and dense clouds embedded in the hot protogalactic medium are assumed to be the progenitors of galactic halo globular clusters. The massive stars of a first generation of metal-free stars, born in the central areas of the proto-globular cluster clouds, explode as Type II supernovae. The associated blast waves trigger the expansion of a supershell, sweeping all the material of the cloud, and the heavy elements released by these massive stars enrich the supershell. A second generation of stars is born in these compressed and enriched layers of gas. These stars can recollapse and form a globular cluster. This work aims at revising the most often encountered argument against self-enrichment, namely the presumed ability of a small number of supernovae to disrupt a proto-globular cluster cloud. We describe a model of the dynamics of the supershell and of its progressive chemical enrichment. We show that the minimal mass of the primordial cluster cloud required to avoid disruption by several tens of Type II supernovae is compatible with the masses usually assumed for proto-globular cluster clouds. Furthermore, the corresponding self-enrichment level is in agreement with halo globular cluster metallicities.

  20. TDR System for Hydraulic Characterization of Unsaturated Soils in the Centrifuge John S. McCartney1

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    TDR System for Hydraulic Characterization of Unsaturated Soils in the Centrifuge John S. McCartney1@mail.utexas.edu Abstract A centrifuge permeameter has been developed to provide expedited determination of the hydraulic bucket. The hydraulic properties of a soil specimen are measured using the centrifuge permeameter

  1. The First Population II Stars Formed in Externally Enriched Mini-halos

    E-Print Network [OSTI]

    Smith, Britton; O'Shea, Brian; Norman, Michael; Khochfar, Sadegh

    2015-01-01T23:59:59.000Z

    We present a simulation of the formation of the earliest Population II stars, starting from cosmological initial conditions and ending when metals created in the first supernovae are incorporated into a collapsing gas-cloud. This occurs after a supernova blast-wave collides with a nearby mini-halo, inducing further turbulence that efficiently mixes metals into the dense gas in the center of the halo. The gas that first collapses has been enriched to a metallicity of Z ~ 2e-5 Zsun. Due to the extremely low metallicity, collapse proceeds similarly to metal-free gas until dust cooling becomes efficient at high densities, causing the cloud to fragment into a large number of low mass objects. This external enrichment mechanism provides a plausible origin for the most metal-poor stars observed, such as SMSS J031300.36-670839.3, that appear to have formed out of gas enriched by a single supernova. This mechanism operates on shorter timescales than the time for low-mass mini-halos (M < 5e5 Msun) to recover their g...

  2. Passive gas separator and accumulator device

    DOE Patents [OSTI]

    Choe, Hwang (Saratoga, CA); Fallas, Thomas T. (Berkeley, CA)

    1994-01-01T23:59:59.000Z

    A separation device employing a gas separation filter and swirler vanes for separating gas from a gasliquid mixture is provided. The cylindrical filter utilizes the principle that surface tension in the pores of the filter prevents gas bubbles from passing through. As a result, the gas collects in the interior region of the filter and coalesces to form larger bubbles in the center of the device. The device is particularly suited for use in microgravity conditions since the swirlers induce a centrifugal force which causes liquid to move from the inner region of the filter, pass the pores, and flow through the outlet of the device while the entrained gas is trapped by the filter. The device includes a cylindrical gas storage screen which is enclosed by the cylindrical gas separation filter. The screen has pores that are larger than those of the filters. The screen prevents larger bubbles that have been formed from reaching and interfering with the pores of the gas separation filter. The device is initially filled with a gas other than that which is to be separated. This technique results in separation of the gas even before gas bubbles are present in the mixture. Initially filling the device with the dissimilar gas and preventing the gas from escaping before operation can be accomplished by sealing the dissimilar gas in the inner region of the separation device with a ruptured disc which can be ruptured when the device is activated for use.

  3. Toxic Substances Control Act Uranium Enrichment Federal Facility...

    Office of Environmental Management (EM)

    Toxic Substances Control Act Uranium Enrichment Federal Facility Compliance Agreement Toxic Substances Control Act Uranium Enrichment Federal Facility Compliance Agreement Toxic...

  4. Oxygen-Enriched Combustion for Military Diesel Engine Generators...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Oxygen-Enriched Combustion for Military Diesel Engine Generators Oxygen-Enriched Combustion for Military Diesel Engine Generators Substantial increases in brake power and...

  5. A Segmented, Enriched N-type Germanium Detector for Neutrinoless...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Publications A Segmented, Enriched N-type Germanium Detector for Neutrinoless Double Beta-Decay Experiments. A Segmented, Enriched N-type Germanium Detector for Neutrinoless...

  6. Highly Enriched Uranium Materials Facility, Major Design Changes...

    Energy Savers [EERE]

    Highly Enriched Uranium Materials Facility, Major Design Changes Late...Lessons Learned Report, NNSA, Dec 2010 Highly Enriched Uranium Materials Facility, Major Design Changes...

  7. N-Terminal Enrichment: Developing a Protocol to Detect Specific...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Terminal Enrichment: Developing a Protocol to Detect Specific Proteolytic Fragments. N-Terminal Enrichment: Developing a Protocol to Detect Specific Proteolytic Fragments....

  8. A Segmented, Enriched N-type Germanium Detector for Neutrinoless...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Segmented, Enriched N-type Germanium Detector for Neutrinoless Double Beta-Decay Experiments. A Segmented, Enriched N-type Germanium Detector for Neutrinoless Double Beta-Decay...

  9. EIS-0471: Areva Eagle Rock Enrichment Facility in Bonneville...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1: Areva Eagle Rock Enrichment Facility in Bonneville County, ID EIS-0471: Areva Eagle Rock Enrichment Facility in Bonneville County, ID May 20, 2011 EIS-0471: Final Environmental...

  10. A Method for Selective Enrichment and Analysis of Nitrotyrosine...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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

  11. Deuterium enrichment by selective photo-induced dissociation of an organic carbonyl compound

    DOE Patents [OSTI]

    Marling, John B. (Livermore, CA)

    1981-01-01T23:59:59.000Z

    A method for producing a deuterium enriched material by photoinduced dissociation which uses as the working material a gas phase photolytically dissociable organic carbonyl compound containing at least one hydrogen atom bonded to an atom which is adjacent to a carbonyl group and consisting of molecules wherein said hydrogen atom is present as deuterium and molecules wherein said hydrogen atom is present as another isotope of hydrogen. The organic carbonyl compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of the deuterium containing species to yield a deuterium enriched stable molecular product. Undissociated carbonyl compound, depleted in deuterium, is preferably redeuterated for reuse.

  12. Metal Enrichment of the Intra-Cluster Medium: Ram-Pressure Stripping of Cluster Galaxies

    E-Print Network [OSTI]

    W. Domainko; W. Kapferer; S. Schindler; E. van Kampen; S. Kimeswenger; M. Mair; M. Ruffert

    2004-05-28T23:59:59.000Z

    We present numerical simulations of the dynamical and chemical evolution of galaxy clusters. X-ray spectra show that the intra-cluster medium contains a significant amount of metals. As heavy elements are produced in the stars of galaxies material from the galaxies must have been expelled to enrich the ambient medium. We have performed hydrodynamic simulations investigating various processes. In this presentation we show the feedback from gas which is stripped from galaxies by ram-pressure stripping. The efficiency, resulting spatial distribution of the metals and the time dependency of this enrichment process on galaxy cluster scale is shown.

  13. Disposition of Surplus Highly Enriched Uranium

    Broader source: Energy.gov (indexed) [DOE]

    four alternatives that would eliminate the weapons-usability of HEU by blending it with depleted uranium, natural uranium, or low-enriched uranium (LEU) to create LEU, either as...

  14. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

    1998-03-24T23:59:59.000Z

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.

  15. Concrete Cleaning, Inc. centrifugal shot blaster: Baseline report; Summary

    SciTech Connect (OSTI)

    NONE

    1997-07-31T23:59:59.000Z

    The centrifugal shot blaster is an electronically operated shot-blast machine that removes layer of concrete of varying depths. Hardened steel shot propelled at a high rate of speed abrades the surface of the concrete. The depth of material removed is determined by the rate of speed the machine is traveling and the volume of shot being fired into the blast chamber. The steel shot is reused until it is pulverized to dust, which is deposited in the waste container with the concrete being removed. Debris is continually vacuumed by a large dust collection system attached to the shot blaster. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  16. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, Stephan T. (Butte, MT); Battleson, Daniel M. (Butte, MT); Rademacher, Jr., Edward L. (Butte, MT); Cashell, Patrick V. (Butte, MT); Filius, Krag D. (Butte, MT); Flannery, Philip A. (Ramsey, MT); Whitworth, Clarence G. (Butte, MT)

    1998-01-01T23:59:59.000Z

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

  17. U. S. forms uranium enrichment corporation

    SciTech Connect (OSTI)

    Seltzer, R.

    1993-07-12T23:59:59.000Z

    After almost 40 years of operation, the federal government is withdrawing from the uranium enrichment business. On July 1, the Department of Energy turned over to a new government-owned entity--the US Enrichment Corp. (USEC)--both the DOE enrichment plants at Paducah, Ky., and Portsmouth, Ohio, and domestic and international marketing of enriched uranium from them. Pushed by the inability of DOE's enrichment operations to meet foreign competition, Congress established USEC under the National Energy Policy Act of 1992, envisioning the new corporation as the first step to full privatization. With gross revenues of $1.5 billion in fiscal 1992, USEC would rank 275th on the Fortune 500 list of top US companies. USEC will lease from DOE the Paducah and Portsmouth facilities, built in the early 1950s, which use the gaseous diffusion process for uranium enrichment. USEC's stock is held by the US Treasury, to which it will pay annual dividends. Martin Marietta Energy Systems, which has operated Paducah since 1984 and Portsmouth since 1986 for DOE, will continue to operate both plants for USEC. Closing one of the two facilities will be studied, especially in light of a 40% world surplus of capacity over demand. USEC also will consider other nuclear-fuel-related ventures. USEC will produce only low-enriched uranium, not weapons-grade material. Indeed, USEC will implement a contract now being completed under which the US will purchase weapons-grade uranium from dismantled Russian nuclear weapons and convert it into low-enriched uranium for power reactor fuel.

  18. Comparison of Digestion Protocols for Microgram Quantities of Enriched Protein Samples

    SciTech Connect (OSTI)

    Hervey, IV, William Judson [ORNL; Strader, Michael B [ORNL; Strader, Michael Brad [National Institutes of Health; Hurst, Gregory {Greg} B [ORNL

    2007-01-01T23:59:59.000Z

    Standard biochemical techniques that are used for protein enrichments, such as affinity isolation and density gradient centrifugation, frequently yield high nanogram to low microgram quantities at a significant expenditure of resources and time. The characterization of selected protein enrichments by the "shotgun" mass spectrometry approach is often compromised by the lack of effective and efficient in-solution proteolysis protocols specifically tailored for these small quantities of proteins. This study compares the results of five different digestion protocols that were applied to 2.5 g portions of protein isolates from two disparate sources: Rhodopseudomonas palustris 70S ribosomal proteins, and Bos taurus microtubule-associated proteins (MAPs). Proteolytic peptides produced according to each protocol in each type of protein isolate were analyzed by one-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effectiveness of each digestion protocol was assessed on the basis of three parameters: number of peptide identifications, number of protein identifications, and sequence coverage. The two protocols using a solvent containing 80% acetonitrile (CH3CN) for trypsin digestions performed as well as, and in some instances better than, protocols employing other solvents and chaotropes in both types of protein isolates. A primary advantage of the 80% CH3CN protocol is that it requires fewer sample manipulation steps.

  19. Enrichment Determination of Uranium in Shielded Configurations

    SciTech Connect (OSTI)

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

    2011-01-01T23:59:59.000Z

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

  20. Enrichment of Heavy Metals in Sediment Resulting from Soil

    E-Print Network [OSTI]

    Quinton, John

    agrochemicals has enriched sediment metal concentrations to toxic levels which breach many accepted standards

  1. Reproducing kernel element method Part III: Generalized enrichment and applications

    E-Print Network [OSTI]

    Li, Shaofan

    Reproducing kernel element method Part III: Generalized enrichment and applications Hongsheng Lu enrichment is proposed to construct the global partition polynomials or to enrich global partition polynomial. This is accomplished by either multiplying enrichment functions with the original global partition poly- nomials

  2. Uncertainty clouds uranium enrichment corporation's plans

    SciTech Connect (OSTI)

    Lane, E.

    1993-03-24T23:59:59.000Z

    An expected windfall to the US Treasury from the sale of the Energy Dept.'s commercial fuel enrichment facilities may evaporate in the next few weeks when the Clinton administration submits its fiscal 1994 budget proposal to Congress, according to congressional and administration officials. Under the Energy Policy Act of 1992, DOE is required to lease two uranium enrichment facilities, Portsmouth, Ohio, and Paducah, KY., to the government-owned US Enrichment Corp. (USEC) by July 1. Estimates by OMB and Treasury indicate a potential yearly payoff of $300 million from the government-owned company's sale of fuel for commercial reactors. Those two facilities use a process of gaseous diffusion to enrich uranium to about 3 percent for use as fuel in commercial power plants. DOE has contracts through at least 1996 to provide about 12 million separative work units (SWUs) yearly to US utilities and others world-wide. But under an agreement signed between the US and Russia last August, at least 10 metric tons, or 1.5 million SWUs, of low-enriched uranium (LEU) blended down from Russia warheads is expected to be delivered to the US starting in 1994. It could be sold at $50 to $60 per SWU, far below what DOE currently charges for its SWUs - $135 per SWU for 70 percent of the contract price and $90 per SWU for the remaining 30 percent.

  3. The observable Metal-enrichment of Radiation-driven+Wind-blown HII Regions in the Wolf-Rayet Stage

    E-Print Network [OSTI]

    Gerhard Hensler; Danica Kroeger; Tim Freyer

    2007-02-11T23:59:59.000Z

    From stellar evolution models and from observations of Wolf-Rayet stars it is known that massive stars are releasing metal-enriched gas in their Wolf-Rayet phase by means of strong stellar winds. Although HII region spectra serve as diagnostics to determine the present-day chemical composition of the interstellar medium, it is not yet reliably explored to what extent the diagnostic HII gas is already contaminated by chemically processed stellar wind matter. In a recent paper, we therefore analyzed our models of radiation-driven and wind-blown HII bubbles around an isolated 85 Msun star with originally solar metallicity with respect to its chemical abundances. Although the hot stellar wind bubble (SWB) is enriched with 14N during the WN phase and even much higher with 12C and 16O during the WC phase of the star, we found that at the end of the stellar lifetime the mass ratios of the traced lements N and O in the warm ionized gas are insignificantly higher than solar, whereas an enrichment of 22% above solar is found for C. The transport of enriched elements from the hot SWB to the cool gas occurs mainly by means of mixing of hot gas with cooler at the backside of the SWB shell.

  4. Forced response of a centrifugal compressor stage due to the impeller-diffuser interaction

    E-Print Network [OSTI]

    Walton, Edward James

    2014-01-01T23:59:59.000Z

    The unsteady pressure field experienced by a centrifugal compressor stage can be dominated by of the impeller-diffuser interaction. The energy of the unsteady field, under certain aerodynamic and structural conditions, is ...

  5. Approaches Toward Achieving Optimum Efficiency in Rerates of Large Centrifugal Compressors

    E-Print Network [OSTI]

    Rudisel, D. A.

    Centrifugal compressors are commonly used within the process industries as prime movers. For many years, plants have been designed with "single train", unspared, major machinery in order to reduce construction, operating, and maintenance costs...

  6. Characterization of the flow field response to vaneless space reduction in centrifugal compressors

    E-Print Network [OSTI]

    Villanueva V., Alfonso D. (Villanueva Villarreal)

    2006-01-01T23:59:59.000Z

    The unsteady three-dimensional flow field for two centrifugal compressors of nearly identical design (one with a marginally smaller impeller-diffuser gap) is interrogated to assess the difference in the time averaged ...

  7. Characterization of unsteady loading due to impeller-diffuser interaction in centrifugal compressors

    E-Print Network [OSTI]

    Lusardi, Christopher (Christopher Dean)

    2012-01-01T23:59:59.000Z

    Time dependent simulations are used to characterize the unsteady impeller blade loading due to imipeller-diffuser interaction in centrifugal compressor stages. The capability of simulations are assessed by comparing results ...

  8. Design and validation of a compact radius centrifuge artificial gravity test platform

    E-Print Network [OSTI]

    Trigg, Chris

    2013-01-01T23:59:59.000Z

    Intermittent exposure to artificial gravity on a short radius centrifuge (SRC) with exercise is a promising, comprehensive countermeasure to the cardiovascular and musculoskeletal deconditioning that occurs as a result of ...

  9. Using Mentor, an Expert System, to Perform Preventative Maintenance and Diagnostics on Centrifugal Chillers

    E-Print Network [OSTI]

    Culp, C.; Mills, R.

    1990-01-01T23:59:59.000Z

    Mentor is an expert system which was developed and introduced in 1986 assists service refrigeration techs to perform the correct preventative maintenance (PM) and diagnostics on centrifugal chillers at the right time. This expert system has...

  10. Single Ion Trapping for the Enriched Xenon Observatory

    SciTech Connect (OSTI)

    Waldman, Samuel J.; /Stanford U., Phys. Dept. /SLAC; ,

    2006-03-28T23:59:59.000Z

    In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of {approx_equal} .010 eV.

  11. Method and apparatus for measuring enrichment of UF6

    DOE Patents [OSTI]

    Hill, Thomas Roy (Santa Fe, NM); Ianakiev, Kiril Dimitrov (Los Alamos, NM)

    2011-06-07T23:59:59.000Z

    A system and method are disclosed for determining the enrichment of .sup.235U in Uranium Hexafluoride (UF6) utilizing synthesized X-rays which are directed at a container test zone containing a sample of UF6. A detector placed behind the container test zone then detects and counts the X-rays which pass through the container and the UF6. In order to determine the portion of the attenuation due to the UF6 gas alone, this count rate may then be compared to a calibration count rate of X-rays passing through a calibration test zone which contains a vacuum, the test zone having experienced substantially similar environmental conditions as the actual test zone. Alternatively, X-rays of two differing energy levels may be alternately directed at the container, where either the container or the UF6 has a high sensitivity to the difference in the energy levels, and the other having a low sensitivity.

  12. Application of oxygen-enriched combustion for locomotive diesel engines. Phase 1

    SciTech Connect (OSTI)

    Poola, R.B.; Sekar, R.R.; Assanis, D.N.

    1996-09-01T23:59:59.000Z

    A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power outputs of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in an increase in net engine power of approximately 13% when intake air with an oxygen content of 28% by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure improves power by only 4%. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment are recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment reduces particulate and visible smoke emissions but increases NO emissions. However, a combination of retarded fuel injection timing and post-treatment of exhaust gases may be adequate to meet the locomotive diesel engine NO{sub x} standards. Exhaust gas after-treatment and heat recovery would be required to realize the full potential of oxygen enrichment. Economic analysis shows that oxygen-enrichment technology is economically feasible and provides high returns on investment. The study also indicates the strong influence of membrane parasitic requirements and exhaust energy recovery on economic benefits. To obtain an economic advantage while using a membrane with higher parasitic power requirements, it is necessary to recover a part of the exhaust energy.

  13. atmospheric trace gas: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Websites Summary: enrichments of 22.8 f 2.2 in the concentrations of Ir, SC and the rare earths relative to Cl chondrites of refractory trace metals from a gas of solar...

  14. Effects of friction factor and slip factor on the performance of a centrifugal slurry pump

    E-Print Network [OSTI]

    Sheth, Ketankumar Kantilal

    1985-01-01T23:59:59.000Z

    in dredging operations, chemical plants, power plants, and for handling coal slurries. For higher discharge pressure requirements, centrifugal slurry pumps are operated in series with up to six stages, 800 horsepower on each stage, and discharge pressures...EFFECTS OF FRICTION FACTOR AND SLIP FACTOR ON THE PERFORMANCE OF A CENTRIFUGAL SLURRY PUMP A Thesis by KETANKUMAR KANTILAL SHETH Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements...

  15. Towards development of an incipient surge detection device for centrifugal compressors

    E-Print Network [OSTI]

    Hassinger, David Alan

    1978-01-01T23:59:59.000Z

    TOWARDS DEVELOPMENT OF AN INCIPIENT SURGE DETECTION DEVICE FOR CENTRIFUGAL COMPRESSORS A Thesis DAVID ALAN HASSINGER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1978 Major Subject: Mechanical Engineering TOWARDS DEVELOPMENT OF AN INCIPIENT SURGE DETECTION DEVICE FOR CENTRIFUGAL COMPRESSORS A Thesis by DAVID ALAN HASSINGER Approved as to style and content by: (Chairman of Committee) (Me...

  16. Investigation of flow in vane-island diffusers in centrifugal compressors

    E-Print Network [OSTI]

    Vandijk, Hanne Nicolaas

    1976-01-01T23:59:59.000Z

    INVESTIGATION OF FLOW IN VANE-ISLAND DIFFUSERS IN CENTRIFUGAL COMPRESSORS A Thesis by HANNE NICOLAAS VANDIJK Submitted to the Graduate College of Texas ASM University 1n partial fulf1llment of the requirement for the degree of MASTER... OF SCIENCE December 1976 Major Subject: Mechan1cal Engineering INVESTIGATION OF FLOW IN VANE-ISLAND DIFFUSERS IN CENTRIFUGAL COMPRESSORS A Thesis by HANNE NICOLAAS VANDIJK Approved as to style and content by: (Chairman of Committee) I (Head...

  17. Viability of mammalian embryos subjected to liposome interaction or centrifugation for gene transfer

    E-Print Network [OSTI]

    Loskutoff, Nadia Mikhail

    1985-01-01T23:59:59.000Z

    VIABILITY OF MAMMALIAN EMBRYOS SUBJECTED TO LIPOSOME INTERACTION OR CENTRIFUGATION FOR GENE TRANSFER A Thesis by NADIA MIKHAIL LOSKUTOFF Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1985 Major Subject: Veterinary Physiology VIABILITY OF MAMMALIAN EMBRYOS SUBJECTED TO LIPOSOME INTERACTION OR CENTRIFUGATION FOR GENE TRANSFER A Thesis by Nadia Mikhail Loskutoff Approved as to style...

  18. Status of gadolinium enrichment technology at LLNL

    SciTech Connect (OSTI)

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

    1993-01-01T23:59:59.000Z

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

  19. Thickening of ultrafine coal-water slurries in a solid-bowl centrifuge

    SciTech Connect (OSTI)

    Pinkerton, A.P.; Klima, M.S.; Morrison, J.L.; Miller, B.G.

    1999-07-01T23:59:59.000Z

    As part of a study being conducted for the Electric Power Research Institute's (EPRI's) Upgraded Coal Interest Group (UCIG) to evaluate ultrafine coal dewatering technologies, testing was carried out to investigate the use of a solid-bowl (high-g) centrifuge for thickening ultrafine coalwater slurries. The objective of this study was to increase the solids concentration to a level suitable for use as a coal-water slurry fuel, while maximizing overall solids recovery. Feed material was collected from the combined discharge (centrate) streams from several screen-bowl centrifuges. These devices are currently being used in a commercial coal cleaning facility to dewater the clean coal product from a froth flotation circuit. Current plant practice is to discharge the centrate to settling ponds. The screen bowl centrate averages 5% solids by weight and contains nearly 60% material finer than 10 {mu}m. The current study examined the effects of operating conditions on centrifuge performance. The test conditions included centrifuge bowl and scroll speeds and volumetric feed rate. In addition to thickening, some cleaning was also achieved, because the finest particles (e.g. < 3 {micro}m), which contained a large percentage of liberated clays, were removed with the bulk of the water. The centrifuge products were analyzed for solids concentration, particle size distribution, and ash content. Size selectivity curves were also used to evaluate centrifuge performance.

  20. Centrifugal force induced by relativistically rotating spheroids and cylinders

    E-Print Network [OSTI]

    Joseph Katz; Donald Lynden-Bell; Jiri Bicak

    2011-02-25T23:59:59.000Z

    Starting from the gravitational potential of a Newtonian spheroidal shell we discuss electrically charged rotating prolate spheroidal shells in the Maxwell theory. In particular we consider two confocal charged shells which rotate oppositely in such a way that there is no magnetic field outside the outer shell. In the Einstein theory we solve the Ernst equations in the region where the long prolate spheroids are almost cylindrical; in equatorial regions the exact Lewis "rotating cylindrical" solution is so derived by a limiting procedure from a spatially bound system. In the second part we analyze two cylindrical shells rotating in opposite directions in such a way that the static Levi-Civita metric is produced outside and no angular momentum flux escapes to infinity. The rotation of the local inertial frames in flat space inside the inner cylinder is thus exhibited without any approximation or interpretational difficulties within this model. A test particle within the inner cylinder kept at rest with respect to axes that do not rotate as seen from infinity experiences a centrifugal force. Although the spacetime there is Minkowskian out to the inner cylinder nevertheless that space has been induced to rotate, so relative to the local inertial frame the particle is traversing a circular orbit.

  1. Planet Migration and Disk Destruction due to Magneto-Centrifugal Stellar Winds

    E-Print Network [OSTI]

    R. V. E. Lovelace; M. M. Romanova; A. W. Barnard

    2008-06-25T23:59:59.000Z

    This paper investigates the influence of magneto-centrifugally driven or simply magnetic winds of rapidly-rotating, strongly-magnetized T Tauri stars in causing the inward or outward migration of close-in giant planets. The azimuthal ram pressure of the magnetized wind acting on the planet tends to increase the planet's angular momentum and cause outward migration if the star's rotation period $P_*$ is less than the planet's orbital period $P_p$. In the opposite case, $P_* > P_p$, the planet migrates inward. Thus, planets orbiting at distances larger (smaller) than $0.06 {\\rm AU}(P_*/5{\\rm d})^{2/3}$ tend to be pushed outward (inward), where $P_*$ is the rotation period of the star assumed to have the mass of the sun. The magnetic winds are likely to occur in T Tauri stars where the thermal speed of the gas close to the star is small, where the star's magnetic field is strong, and where the star rotates rapidly. The time-scale for appreciable radial motion of the planet is estimated as $\\sim 2 - 20$ Myr. A sufficiently massive close-in planet may cause tidal locking and once this happens the radial migration due to the magnetic wind ceases. The magnetic winds are expected to be important for planet migration for the case of a multipolar magnetic field rather than a dipole field where the wind is directed away from the equatorial plane and where a magnetospheric cavity forms. The influence of the magnetic wind in eroding and eventually destroying the accretion disk is analyzed. A momentum integral is derived for the turbulent wind/disk boundary layer and this is used to estimate the disk erosion time-scale as $\\sim 1-10^2$ Myr, with the lower value favored.

  2. Method for laser induced isotope enrichment

    DOE Patents [OSTI]

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

    2004-09-07T23:59:59.000Z

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

  3. Starbursts and their contribution to metal enrichment

    E-Print Network [OSTI]

    Kunth Daniel

    2007-04-28T23:59:59.000Z

    I review the properties of starburst galaxies, compare the properties of the local ones with more distant starburts and examine their role in the metal enrichment of the interstellar medium and the intergalactic-intracluster medium. Metallicity is not an arrow of time and contrary to current belief metal rich galaxies can also be found at high redshift.

  4. A Resolution of the Paradox of Enrichment

    E-Print Network [OSTI]

    Z. C. Feng; Y. Charles Li

    2013-03-11T23:59:59.000Z

    The paradox of enrichment was observed by M. Rosenzweig in a class of predator-prey models. Two of the parameters in the models are crucial for the paradox. These two parameters are the prey's carrying capacity and prey's half-saturation for predation. Intuitively, increasing the carrying capacity due to enrichment of the prey's environment should lead to a more stable predator-prey system. Analytically, it turns out that increasing the carrying capacity always leads to an unstable predator-prey system that is susceptible to extinction from environmental random perturbations. This is the so-called paradox of enrichment. Our resolution here rests upon a closer investigation on a dimensionless number $H$ formed from the carrying capacity and the prey's half-saturation. By recasting the models into dimensionless forms, the models are in fact governed by a few dimensionless numbers including $H$. The effects of the two parameters: carrying capacity and half-saturation are incorporated into the number $H$. In fact, increasing the carrying capacity is equivalent (i.e. has the same effect on $H$) to decreasing the half-saturation which implies more aggressive predation. Since there is no paradox between more aggressive predation and instability of the predator-prey system, the paradox of enrichment is resolved. We also further explore spatially dependent models for which the phase space is infinite dimensional. The spatially independent limit cycle which is generated by a Hopf bifurcation from an unstable steady state, is linearly stable in the infinite dimensional phase space. Numerical simulations indicate that the basin of attraction of the limit cycle is riddled. This shows that spatial perturbations can sometimes (neither always nor never) remove the paradox of enrichment near the limit cycle!

  5. The Economics of Oxygen Enriched Air Production Via Membranes

    E-Print Network [OSTI]

    Gollan, A.; Kleper, M. H.

    1984-01-01T23:59:59.000Z

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

  6. Paducah and Portsmouth Off-Specification Enriched and Normal...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Enriched and Normal UF 6 Inventory 1 3B refers to a 30B cylinder size and 4A refers to a 48A size cylinder. Table 1 PORTS Enriched Inventory Container ID Sample Transfer Gross lbs...

  7. Enriching personal information management with document interaction histories

    E-Print Network [OSTI]

    Whitton, Mary C.

    Enriching personal information management with document interaction histories by Karl Gyllstrom;Abstract KARL GYLLSTROM: Enriching personal information management with document interaction histories. (Under the direction of David Stotts.) Personal information management is increasingly challenging

  8. CenterPoint The Center for Academic Enrichment & Outreach Newsletter

    E-Print Network [OSTI]

    Hemmers, Oliver

    CenterPoint March 2010 The Center for Academic Enrichment & Outreach Newsletter ONLINE ARTICLES and outreach and the executive director for The Center for Academic Enrichment and Outreach (The Center

  9. CenterPoint The Center for Academic Enrichment & Outreach Newsletter

    E-Print Network [OSTI]

    Hemmers, Oliver

    CenterPoint April 2011 The Center for Academic Enrichment & Outreach Newsletter ONLINE ARTICLES's Center for Academic Enrichment and Outreach (The Center) and funded by competitive grants from the U

  10. The use of a solid-bowl centrifuge for ultrafine coal thickening

    SciTech Connect (OSTI)

    Pinkerton, A.P.; Klima, M.S.; Morrison, J.L.; Miller, B.G.

    2000-07-01T23:59:59.000Z

    Testing was carried out to investigate the use of a solid-bowl (decanter) centrifuge for thickening ultrafine coal-water slurries. This study was conducted for Electric Power Research Institute's (EPRI's) Upgraded Coal Interest Group (UCIG) to evaluate ultrafine dewatering technologies. The objective was to increase the solids concentration of an ultrafine coal discard stream to a level suitable for use as a coal-water slurry fuel, while maximizing overall solids recovery. The feed material was collected from the combined discharge (centrate) streams from several screen-bowl centrifuges, which are currently being used in a commercial coal cleaning facility to dewater froth flotation product. The centrate averages 5% solids by weight and contains nearly 60% material finer than 10 {micro}m. This study examined the effects of operating conditions on centrifuge performance, including centrifuge bowl and scroll speeds, and feed solids concentration. The effects of flocculation addition on centrifuge performance and slurry rheology were also examined. The results indicated that solids concentrations exceeding 55% were obtained in nearly all cases.

  11. High potential recovery -- Gas repressurization

    SciTech Connect (OSTI)

    Madden, M.P.

    1998-05-01T23:59:59.000Z

    The objective of this project was to demonstrate that small independent oil producers can use existing gas injection technologies, scaled to their operations, to repressurize petroleum reservoirs and increase their economic oil production. This report gives background information for gas repressurization technologies, the results of workshops held to inform small independent producers about gas repressurization, and the results of four gas repressurization field demonstration projects. Much of the material in this report is based on annual reports (BDM-Oklahoma 1995, BDM-Oklahoma 1996, BDM-Oklahoma 1997), a report describing the results of the workshops (Olsen 1995), and the four final reports for the field demonstration projects which are reproduced in the Appendix. This project was designed to demonstrate that repressurization of reservoirs with gas (natural gas, enriched gas, nitrogen, flue gas, or air) can be used by small independent operators in selected reservoirs to increase production and/or decrease premature abandonment of the resource. The project excluded carbon dioxide because of other DOE-sponsored projects that address carbon dioxide processes directly. Two of the demonstration projects, one using flue gas and the other involving natural gas from a deeper coal zone, were both technical and economic successes. The two major lessons learned from the projects are the importance of (1) adequate infrastructure (piping, wells, compressors, etc.) and (2) adequate planning including testing compatibility between injected gases and fluids, and reservoir gases, fluids, and rocks.

  12. Metal Enrichment in the Intra-Cluster Medium

    E-Print Network [OSTI]

    Sabine Schindler

    2006-11-20T23:59:59.000Z

    The enrichment of the Intra-Cluster Medium (ICM) with heavy elements is reviewed. There is now good observational evidence for enrichment including abundance ratios and metallicity distributions. Various processes involved in the enrichment process -- ram-pressure stripping, galactic winds, galaxy-galaxy interactions, AGN outflows and intra-cluster supernovae -- are described. Simulations of the ICM evolution taking into account metal enrichment are presented.

  13. Nitrous Oxide Nitrification and Denitrification 15N Enrichment Factors from Amazon Forest Soils

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    M. Wahlen. 1997. Stable isotope enrichment in stratosphericthat we know the isotope enrichment factors for nitri?cationmethod for measuring N isotope enrichment factors for nitri?

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

    E-Print Network [OSTI]

    Hamilton, Matthew

    2010-01-01T23:59:59.000Z

    Robotic Enrichment Processing of Roche 454 Titanium EmulsionLaboratory Abstract Enrichment of emulsion PCR product isergonomic demands of the 454 enrichment process. The robot

  15. High-solids enrichment of thermophilic microbial communities and their enzymes on bioenergy feedstocks

    E-Print Network [OSTI]

    Reddy, A. P.

    2012-01-01T23:59:59.000Z

    High-solids enrichment of thermophilic microbial communities5, upon four successive enrichments on switchgrass. Overall,the first and second enrichments increased 4-fold for

  16. SNP-based pathway enrichment analysis for genome-wide association studies

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    SNP: applying gene set enrichment analysis to SNP data fromdetection of pathway enrichment in genome-wide associational. : SNP-based pathway enrichment analysis for genome-wide

  17. Nitrous Oxide Nitrification and Denitrification 15N Enrichment Factors from Amazon Forest Soils

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    1997. Stable isotope enrichment in stratospheric nitrouson the apparent enrichment factors and the isotopologue ?differentiated in this manner. Enrichments in 18 O have been

  18. Enrichment, isolation and characterization of fungi tolerant to 1-ethyl-3-methylimidazolium acetate

    E-Print Network [OSTI]

    Singer, S.W.

    2012-01-01T23:59:59.000Z

    Enrichment, isolation and characterization of fungi tolerantMethods and Results: Enrichment experiments performed usingisolates from these enrichments were capable of growing in a

  19. Uranium enrichment export control guide: Gaseous diffusion

    SciTech Connect (OSTI)

    Not Available

    1989-09-01T23:59:59.000Z

    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.

  20. ECOLOGY AND POPULATION BIOLOGY Enhanced Carbon Enrichment in Parasitoids (Hymenoptera)

    E-Print Network [OSTI]

    Rosenheim, Jay A.

    (2): 205Đ213 (2005) ABSTRACT By considering the magnitude of isotope enrichment associated with trophicŢcult. Several recent reviews have estimated that consumers become enriched in the heavy nitrogen isotope that consumers become enriched in the heavy carbon isotope between 0.4 and 0.5 per trophic transfer. Although

  1. Predation, Enrichment, and Phytoplankton Community Structure Michael Lynch; Joseph Shapiro

    E-Print Network [OSTI]

    Lynch, Michael

    Predation, Enrichment, and Phytoplankton Community Structure Michael Lynch; Joseph Shapiro@jstor.org. http://www.jstor.org Thu Aug 30 11:57:16 2007 #12;Predation, enrichment, and phytoplankton community and enrichment to the Pleasant Pond phytoplankton community was examined through a series of enclosure

  2. CARBON ENRICHMENT IN RESIDUAL AUSTENITE DURING MARTENSITIC TRANSFORMATION

    E-Print Network [OSTI]

    Cambridge, University of

    179 CARBON ENRICHMENT IN RESIDUAL AUSTENITE DURING MARTENSITIC TRANSFORMATION S. W. Ooi1 , Y. R, retained austenite, autotempering and low carbon steel. Abstract Carbon enrichment of austenite and carbide enrich with carbon [9-11] and there has been recent work to exploit this process in the design of `quench

  3. TRAINING PENGUINS TO INTERACT WITH ENRICHMENT ITEMS FOR LASTING EFFECTS

    E-Print Network [OSTI]

    Timberlake, William D.

    TRAINING PENGUINS TO INTERACT WITH ENRICHMENT ITEMS FOR LASTING EFFECTS Eduardo J. Fernandez decades, zoo have begun to focus more on the use of enrichment to promote the "well-being" of their animals, (Markowitz & Aday, 1998). One purpose of enrichment is to promote more naturalistic behaviors

  4. College Enrichment Program(CEP) New Student Orientation

    E-Print Network [OSTI]

    New Mexico, University of

    College Enrichment Program(CEP) New Student Orientation Summer 2011 In the Division of Student Affairs #12;2 Table of Contents UNM Phone Numbers 3 Welcome Letter 4 What is the College Enrichment Welcome Back BBQ 14 Campus Map 15 #12;3 UNM Phone Numbers College Enrichment Program 277-5321 Admissions

  5. Research Report Sensory experience determines enrichment-induced plasticity

    E-Print Network [OSTI]

    Kilgard, Michael P.

    Research Report Sensory experience determines enrichment-induced plasticity in rat auditory cortex in an enriched environment increases response strength and paired-pulse depression in the auditory cortex.L., Kilgard, M.P., 2004. Environmental enrichment improves response strength, threshold, selectivity

  6. Larry H. & Gail Miller Enrichment Scholarship Fall 2015 Application Information

    E-Print Network [OSTI]

    Feschotte, Cedric

    Larry H. & Gail Miller Enrichment Scholarship Fall 2015 Application Information The University benefits and enriches the educational experiences of all students, faculty and staff. Thus the U strives/leadership service. The Miller Enrichment Scholarship award may include any or all of the following benefits: Full

  7. Evaluating mechanisms of nutrient depletion and 13 C enrichment

    E-Print Network [OSTI]

    Sigman, Daniel M.

    Evaluating mechanisms of nutrient depletion and 13 C enrichment in the intermediate-depth Atlantic to evaluate competing hypotheses for the cause of observed nutrient depletion and 13 C enrichment isotopic equilibration at low temperatures (i.e., 13C enrichment). Although this export adds nutrients

  8. ENVIRONMENTAL ENRICHMENT REDUCES THE MNEMONIC AND NEURAL BENEFITS OF ESTROGEN

    E-Print Network [OSTI]

    Frick, Karyn M.

    ENVIRONMENTAL ENRICHMENT REDUCES THE MNEMONIC AND NEURAL BENEFITS OF ESTROGEN J. E. GRESACKa AND K response to estrogen. Female mice were raised in standard (SC) or enriched (EC) condi- tions from weaning protein synaptophysin and of brain- derived neurotrophic factor (BDNF) were measured. Enrich- ment effects

  9. Cost/performance comparison between pulse columns and centrifugal contactors designed to process Clinch River Breeder Reactor fuel

    SciTech Connect (OSTI)

    Ciucci, J.A. Jr.

    1983-12-01T23:59:59.000Z

    A comparison between pulse columns and centrifugal contactors was made to determine which type of equipment was more advantageous for use in the primary decontamination cycle of a remotely operated fuel reprocessing plant. Clinch River Breeder Reactor (CRBR) fuel was chosen as the fuel to be processed in the proposed 1 metric tonne/day reprocessing facility. The pulse columns and centrifugal contactors were compared on a performance and total cost basis. From this comparison, either the pulse columns or the centrifugal contactors will be recommended for use in a fuel reprocessing plant built to reprocess CRBR fuel. The reliability, solvent exposure to radiation, required time to reach steady state, and the total costs were the primary areas of concern for the comparison. The pulse column units were determined to be more reliable than the centrifugal contactors. When a centrifugal contactor motor fails, it can be remotely changed in less than one eight hour shift. Pulse columns expose the solvent to approximately five times as much radiation dose as the centrifugal contactor units; however, the proposed solvent recovery system adequately cleans the solvent for either case. The time required for pulse columns to reach steady state is many times longer than the time required for centrifugal contactors to reach steady state. The cost comparison between the two types of contacting equipment resulted in centrifugal contactors costing 85% of the total cost of pulse columns when the contactors were stacked on three levels in the module. If the centrifugal contactors were all positioned on the top level of a module with the unoccupied volume in the module occupied by other equipment, the centrifugal contactors cost is 66% of the total cost of pulse columns. Based on these results, centrifugal contactors are recommended for use in a remotely operated reprocessing plant built to reprocess CRBR fuel.

  10. The metal enrichment of elliptical galaxies in hierarchical galaxy formation models

    E-Print Network [OSTI]

    Masahiro Nagashima; Cedric G. Lacey; Takashi Okamoto; Carlton M. Baugh; Carlos S. Frenk; Shaun Cole

    2005-07-14T23:59:59.000Z

    We investigate the metal enrichment of elliptical galaxies in the framework of hierarchical models of galaxy formation. The semi-analytical model we use in this Letter, which has been used to study the metal enrichment of the intracluster medium (ICM) by Nagashima et al., includes the effects of flows of gas and metals both into and out of galaxies and the processes of metal enrichment due to both type Ia and type II supernovae. We adopt a solar neighbourhood IMF for star formation in discs, but consider models in which starbursts have either a solar neighbourhood IMF or a top-heavy IMF. We find that the alpha-element abundance in ellipticals is consistent with observed values only if the top-heavy IMF is used. This result is consistent with our previous study on the metal enrichment of the ICM. We also discuss the abundance ratio of alpha elements to iron as a function of velocity dispersion and metallicity. We find that models with a top-heavy IMF match the alpha/Fe ratios observed in typical L_* ellipticals, but none of the models reproduce the observed increase of alpha/Fe with velocity dispersion.

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

    SciTech Connect (OSTI)

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

    2012-06-07T23:59:59.000Z

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

  12. Inhomogeneous chemical evolution of the Galactic disk: evidence for sequential stellar enrichment?

    E-Print Network [OSTI]

    Bob van den Hoek; Teije de Jong

    1996-07-08T23:59:59.000Z

    We investigate the origin of the abundance variations observed among similarly aged F and G dwarfs in the local Galactic disk. We present arguments in support of combined infall of metal-deficient gas and sequential enrichment by successive stellar generations in the local Galactic disk ISM. We show that galactic chemical evolution models which take into account these processes simultaneously are consistent with both the observed abundance variations among similarly aged dwarfs in the solar neighbourhood and the abundances observed in the local disk ISM. For reasonable choices of parameters, these models can reproduce variations in [M/H] for individual elements M = C, O, Fe, Mg, Al, and Si as well as the scatter observed in abundance-abundance relations like [O/Fe]. For the same models, the contribution of sequential stellar enrichment to the magnitude of the observed abundance variations can be as large as 50%. We discuss the impact of sequential stellar enrichment and episodic infall of metal-deficient gas on the inhomogeneous chemical evolution of the Galactic disk.

  13. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

    E-Print Network [OSTI]

    G. B. Andresen; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; P. D. Bowe; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; A. Deller; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; A. J. Humphries; R. Hydomako; S. Jonsell; N. Madsen; S. Menary; P. Nolan; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele; Y. Yamazaki

    2011-04-26T23:59:59.000Z

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  14. A Fuzzy Feed-Forward/Feedback Control System for a Three-Phase Oil Field Centrifuge.

    SciTech Connect (OSTI)

    Parkinson, W. J. (William Jerry),; Smith, R. E. (Ronald E.); Mortensen, F. N. (Fred N.); Wantuck, P. J. (Paul J.); Ross, Timothy J.; Jamshidi, Mohammad; Miller, N. (Neal)

    2002-01-01T23:59:59.000Z

    A set of fuzzy controllers was designed and applied to a commercial three-phase oil field centrifuge. This centrifuge is essentially a one of a kind unit. It is used to recover oil from tank bottoms and oil field and/or refinery sludge. It is unique because it can separate oily emulsions into three separate phases, oil, water, and solids, in one operation. The centrifuge is a large but portable device. It is moved form site to site and is used to separate a large variety of waste emulsions. The centrifuge feedstock varies significantly from site to site and often varies significantly during the daily operation. In this application, fuzzy logic was used on a class of problems not easily solved by classical control techniques. The oil field centrifuge is a highly nonlinear system, with a time varying input. We have been unable to develop a physical-mathematical model of the portion of the centrifuge operation that actually separates the oil, water, and solids. For this portion of the operation we developed a fuzzy feedback control system that modeled a skilled operator's knowledge and actions as opposed to the physical model of the centrifuge itself. Because of the variable feed we had to develop a feed-forward controller that would sense and react to feed changes prior to the time that the actual change reached the centrifuge separation unit. This portion of the control system was also a fuzzy controller designed around the knowledge of a skilled operator. In addition to the combined feed-forward and feedback control systems, we developed a soft-sensor that was used to determine the value of variables needed for the feed-forward control system. These variables could not actually be measured but were calculated from the measurement of other variables. The soft-sensor was developed with a combination of a physical model of the feed system and a skilled operator's expert knowledge. Finally the entire control system is tied together with a fuzzy-SPC (Statistical Process Control) filter, used to filter process and instrument noise and a fuzzy conflict resolution code used to keep the feed-forward and feedback control systems working well together.

  15. Speed and surge control for a low order centrifugal compressor model Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Speed and surge control for a low order centrifugal compressor model Jan Tommy Gravdahl and Olav Previous work on stabilization of compressor surge is extended to include control of the angular velocity of the compressor. First a low order centrifugal compressor model is presented where the states are mass ow

  16. Measurements of Low-Enriched Uranium Holdup.

    SciTech Connect (OSTI)

    Belian, A. P. (Anthony P.); Reilly, T. D. (T. Douglas); Russo, P. A. (Phyllis A.); Tobin, S. J. (Stephen J.)

    2005-01-01T23:59:59.000Z

    A recent effort determined uranium holdup at a large fuel fabrication facility abroad where low enriched ({approx} 3%) uranium (LEU) oxide feeds the pellet manufacturing process. Measurements taken with both high- and low-resolution gamma-ray spectrometry systems include extensive data for the ventilation and vacuum systems. Equipment dimensions and the corresponding holdup deposit masses are large for LEU. Because deposits are infinitely thick to the 186 keV gamma ray in many locations in an LEU environment, measurements of both the 186 and 1001 keV gamma-rays were required, and self-attenuation was significant at 1001 keV in many cases. These wide-dynamic-range measruements used short count times, portable scintillator detectors, and portable MCAs. Because equipment is elevated above floor levels, most measurements were made with detectors mounted on extended telescoping poles. One of the main goals of this effort was to demonstrate and validate methods for measurement and quantitative analysis of LEU holdup using low-resolution detectors and the Generalized Geometry Holdup (GGH) techniques. The current GGH approach is applied elsewhere for holdup measurements of plutonium and high-enriched uranium. The recent experience is directly applicable to holdup measruements at LEU facilities such as the Paducah and Portmouth gaseous diffusion enrichment plants and elsewhere, including LEU sites where D and D is active. This report discusses the measurement methodology, calibration of the measurement equipment, measurement control, analysis of the data, and the global and local assay results including random and systematic uncertainties. It includes field-validation exercises (multiple calibrated systems that perform measruements on the same extended equipment) as well as quantitative validation results obtained on reference materials assembled to emulate the deposits in an extended vacuum line that was also measured by these techniques. The paper examines the differences in assay results between the low-resolution system using the GGH method and the high-resolution system utilizing the commercially available ISOCS analysis method.

  17. Simulations of Cosmic Chemical Enrichment with Hypernova

    E-Print Network [OSTI]

    Chiaki Kobayashi

    2006-11-27T23:59:59.000Z

    We simulate cosmic chemical enrichment with a hydrodynamical model including supernova and hypernova feedback. We find that the majority of stars in present-day massive galaxies formed in much smaller galaxies at high redshifts, despite their late assembly times. The hypernova feedback drives galactic outflows efficiently in low mass galaxies, and these winds eject heavy elements into the intergalactic medium. The ejected baryon fraction is larger for less massive galaxies, correlates well with stellar metallicity. The observed mass-metallicity relation is well reproduced as a result of the mass-dependent galactic winds. We also predict the cosmic supernova and gamma-ray burst rate histories.

  18. Backfill Stress and Strain Information within a Centrifuge Geosynthetic-Reinforced Slope Model under Working Stress and Large Soil Strain Conditions

    E-Print Network [OSTI]

    Zornberg, Jorge G.

    Backfill Stress and Strain Information within a Centrifuge Geosynthetic-Reinforced Slope Model with a centrifuge test are used to investigate the mobilization of backfill stress and strain within a geosynthetic a centrifuge GRS slope model. Numerical results indicate that soil stress mobilization can be described

  19. Laser velocimetry study of the flow field in a centrifugal pump with a shrouded impeller

    E-Print Network [OSTI]

    Moran, Michael Kevin

    1994-01-01T23:59:59.000Z

    This study provides laser velocimetry measurements of the flow field within a centrifugal pump. The pump had a shrouded impeller of 254 mm diameter with five blades of backswept design. Measurements were made using a laser-two-focus (L2F...

  20. Title of dissertation: H & NEUTRAL DENSITY SCALING IN THE MARYLAND CENTRIFUGAL EXPERI-

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of dissertation: H & NEUTRAL DENSITY SCALING IN THE MARYLAND CENTRIFUGAL EXPERI- MENT M. Ryan Clary, Doctor of Philosophy, 2009 Dissertation directed by: Professor Richard Ellis confinement time as well as to scale differently than the momentum confinement time. This dissertation

  1. An analysis of shaft/shaft seal interaction of a multiple disk centrifugal blood pump

    E-Print Network [OSTI]

    Manning, Keefe Baird

    1997-01-01T23:59:59.000Z

    A multiple disk centrifugal blood pump is in the early stages of development. As is the case with most pumps that are shaft driven, leakage problems around the shaft/shaft seal interface are of major interest. If leakage were to occur during...

  2. WAVE-DRIVEN ROTATION IN CENTRIFUGAL MIRRORS Abraham J. Fetterman and Nathaniel J. Fisch

    E-Print Network [OSTI]

    by harnessing alpha particle energy. This is an exten- sion of the alpha channeling effect. The alpha particleWAVE-DRIVEN ROTATION IN CENTRIFUGAL MIRRORS Abraham J. Fetterman and Nathaniel J. Fisch Department frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation

  3. Expression des constantes de distorsion centrifuge des hexafluorures en fonction des frquences harmoniques.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    'application est faite aux molécules SF6 et UF6. 4 constantes cubiques de SF6 ont été déterminées à partir des for the centrifugal distortion constants as a function of harmonic frequencies ; application is made to SF6 and UF6. 4

  4. Bond Graph Modeling of Centrifugal Compressor System Nur Uddin and Jan Tommy Gravdahl

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Bond Graph Modeling of Centrifugal Compressor System Nur Uddin and Jan Tommy Gravdahl Dept, Norway N-7491 nur.uddin@itk.ntnu.no, Jan.Tommy.Gravdahl@itk.ntnu.no Keywords: Compressor, compressor. A model of a compression system with recycle flow is derived in this work. 1. INTRODUCTION Compressors

  5. Drive actuation in active control of centrifugal compressors Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Drive actuation in active control of centrifugal compressors Jan Tommy Gravdahl and Olav Egeland-1375 Billingstad NORWAY CompressorShaft Electric drive Active surge control law Shaft speed Compressor compressor surge has been avoided using surge avoidance schemes that use various techniques to keep

  6. Elimination of Adverse Leakage Flow in a Miniature Pediatric Centrifugal Blood Pump by Computational Fluid Dynamics

    E-Print Network [OSTI]

    Paden, Brad

    levitated centrifugal blood pump intended to deliver 0.3­1.5 l/min of support to neo- nates and infants computational fluid dy- namics (CFD) analysis of impeller refinements, we found that sec- ondary blades located by exten- sive in vitro model testing. Computational fluid dynamics (CFD) has been widely used

  7. Effect of the Centrifugal Force on Domain Chaos in Rayleigh-Bénard convection

    E-Print Network [OSTI]

    Nathan Becker; J. D. Scheel; M. C. Cross; Guenter Ahlers

    2005-11-15T23:59:59.000Z

    Experiments and simulations from a variety of sample sizes indicated that the centrifugal force significantly affects rotating Rayleigh-B\\'enard convection-patterns. In a large-aspect-ratio sample, we observed a hybrid state consisting of domain chaos close to the sample center, surrounded by an annulus of nearly-stationary nearly-radial rolls populated by occasional defects reminiscent of undulation chaos. Although the Coriolis force is responsible for domain chaos, by comparing experiment and simulation we show that the centrifugal force is responsible for the radial rolls. Furthermore, simulations of the Boussinesq equations for smaller aspect ratios neglecting the centrifugal force yielded a domain precession-frequency $f\\sim\\epsilon^\\mu$ with $\\mu\\simeq1$ as predicted by the amplitude-equation model for domain chaos, but contradicted by previous experiment. Additionally the simulations gave a domain size that was larger than in the experiment. When the centrifugal force was included in the simulation, $\\mu$ and the domain size closely agreed with experiment.

  8. Water balance in rats exposed to chronic centrifugation RUDY M. ORTIZ AND CHARLES E. WADE

    E-Print Network [OSTI]

    Ortiz, Rudy M.

    was observed, the lack of a change in %TBW among the three measurement periods or in water flux over the 12Water balance in rats exposed to chronic centrifugation RUDY M. ORTIZ AND CHARLES E. WADE Life; accepted in final form 22 February 2000 Ortiz, Rudy M., and Charles E. Wade. Water balance in rats exposed

  9. genomic DNA was isolated from these centrifuged cell pellets and used for am-

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    genomic DNA was isolated from these centrifuged cell pellets and used for am- plification of either changes in ruminal bacterial popula- tions. J Wood1, KP Scott,1, G Avguštin2,J Wood1 KP Scott, G of this group from rumen- extracted DNA. Restriction enzyme cleav- age of the PCR product yields profiles

  10. ON CENTRIFUGAL SETTLING OF POLYDISPERSE SUSPENSIONS WITH A CONTINUOUS PARTICLE SIZE DISTRIBUTION

    E-Print Network [OSTI]

    Bürger, Raimund

    -density particles [3]. The settling of an N-disperse suspension, including the formation of sediment, can@ucn.cl ABSTRACT Gravity or centrifugal sedimentation of polydisperse suspensions with a continuous particle size distribution (PSD) can be modelled by a kinetic equation, which represents the limit case of a system

  11. Metal Enrichment in the Early Galactic Halo

    E-Print Network [OSTI]

    C. Ikuta; N. Arimoto

    1999-06-14T23:59:59.000Z

    An early history of metal enrichment in the Galactic halo is studied. We investigate chemical inhomogeneity by using a stochastic chemical evolution model. The model confronts with metallicity distribution function of long-lived halo stars which is found to be a clue to obtain the best model prescriptions. We find that the star formation in the halo virtually terminated by around 1 Gyr and that the halo has never been chemically homogeneous in its star formation history. This conclusion does not depend whether mass loss from the halo is taken into account or not. Observed ratios of alpha-elements with respect to iron do not show scatters on a [alpha/Fe]-[Fe/H] plane, but this does not imply that interstellar matter in the halo was homogeneous because a chemical evolution path on this diagram is degenerate in the star formation rate. On the other hand, apparent spread of [Sr/Fe] ratio among metal-poor halo stars does not reflect an inhomogeneous metal enrichment, instead it is due to a sharp increase in a production rate of strontium that is probably synthesised in slightly less massive stars than progenitor of iron-producing SNII.

  12. Oxygen Enriched Combustion System Performance Study

    E-Print Network [OSTI]

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

    determined with detailed measurements. The detailed measurements, including furnace gas temperature profile, total and radiant heat flux, will be integrated and evaluated with a numerical heat transfer model. The model will then be used to extrapolate...

  13. Comparison of average and point capillary pressure-saturation functions determined by steady-state centrifugation

    SciTech Connect (OSTI)

    Cropper, Clark [University of Tennessee, Knoxville (UTK); Perfect, Edmund [ORNL; van den Berg, Dr. Elmer [University of Tennessee, Knoxville (UTK); Mayes, Melanie [ORNL

    2010-01-01T23:59:59.000Z

    The capillary pressure-saturation function can be determined from centrifuge drainage experiments. In soil physics, the data resulting from such experiments are usually analyzed by the 'averaging method.' In this approach, average relative saturation, , is expressed as a function of average capillary pressure, <{psi}>, i.e., (<{psi}>). In contrast, the capillary pressure-saturation function at a physical point, i.e., S({psi}), has been extracted from similar experiments in petrophysics using the 'integral method.' The purpose of this study was to introduce the integral method applied to centrifuge experiments to a soil physics audience and to compare S({psi}) and (<{psi}>) functions, as parameterized by the Brooks-Corey and van Genuchten equations, for 18 samples drawn from a range of porous media (i.e., Berea sandstone, glass beads, and Hanford sediments). Steady-state centrifuge experiments were performed on preconsolidated samples with a URC-628 Ultra-Rock Core centrifuge. The angular velocity and outflow data sets were then analyzed using both the averaging and integral methods. The results show that the averaging method smoothes out the drainage process, yielding less steep capillary pressure-saturation functions relative to the corresponding point-based curves. Maximum deviations in saturation between the two methods ranged from 0.08 to 0.28 and generally occurred at low suctions. These discrepancies can lead to inaccurate predictions of other hydraulic properties such as the relative permeability function. Therefore, we strongly recommend use of the integral method instead of the averaging method when determining the capillary pressure-saturation function by steady-state centrifugation. This method can be successfully implemented using either the van Genuchten or Brooks-Corey functions, although the latter provides a more physically precise description of air entry at a physical point.

  14. Heat release analysis of oxygen-enriched diesel combustion

    SciTech Connect (OSTI)

    Assanis, D.; Karvounis, E. (Univ. of Illinois, Urbana, IL (United States)); Sekar, R.; Marr, W. (Argonne National Lab., IL (United States))

    1993-10-01T23:59:59.000Z

    A heat release correlation for oxygen-enriched diesel combustion is being developed through heat release analysis of cylinder pressure data from a single-cylinder diesel engine operating under various levels of oxygen enrichment. Results show that standard combustion correlations available in the literature do not accurately describe oxygen-enriched diesel combustion. A novel functional form is therefore proposed, which is shown to reproduce measured heat release profiles closely, under different operating conditions and levels of oxygen enrichment. The mathematical complexity of the associated curve-fitting problem is maintained at the same level of difficulty as for standard correlations. When the novel correlation is incorporated into a computer simulation of diesel engine operation with oxygen enrichment, the latter predicts pressure traces in excellent agreement with measured pressure data. This demonstrates the potential of the proposed combustion simulation to guide the application of oxygen-enriched technology successfully to a variety of multicylinder diesel systems.

  15. Assuaging Nuclear Energy Risks: The Angarsk International Uranium Enrichment Center

    SciTech Connect (OSTI)

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

    2011-06-28T23:59:59.000Z

    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.

  16. Current status and future plan of uranium enrichment technology

    SciTech Connect (OSTI)

    Yonekawa, S.; Yamamoto, F.; Yato, Y.; Kishimoto, Y. [PNC, Ningyo-Toge (Japan)

    1994-12-31T23:59:59.000Z

    The Power Reactor and Nuclear Fuel Development Corporation (PNC) has been conducting extensive research and development (R&D) on the centrifuge process for more than a quarter of a century. This development program, designated as a national project in 1972, has resulted in the construction and operation of a pilot plant with a capacity of 50 t separative work unit (SWU) per year as well as a demonstration plant with a capacity of 200 t SWU/yr. Under the basic agreement of cooperation concluded in 1985, the technology developed in this program has been transferred to Japan Nuclear Fuel Limited (JNFL), which is now constructing and operating the commercial plant with a capacity of 1500 t SWU/yr at Rokkasho, Aomori. This paper describes the operational experiences of the demonstration plant, the status of a new material centrifuge, which will be introduced at a later stage of construction of the commercial plant, the development of an advanced centrifuge as a next-generation machine, and the research of a superadvanced centrifuge.

  17. Enriched Stable Isotope Materials and Chemistry | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Chemistry SHARE Enriched Stable Isotope Materials and Chemistry Reductiondistillation of calcium-48 metal valued at over 900,000. An inventory of 2,300 batches of...

  18. activity enantiomerically enriched: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Li-enrichment. Doppler imaging was applied to recover the surface temperature distribution of DI Psc in two subsequent rotational cycles using the individual mapping lines Ca...

  19. NNSA and Kazakhstan Complete Operation to Eliminate Highly Enriched...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Kazakhstan Complete Operation to Eliminate Highly Enriched Uranium | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the...

  20. Enrichment of Functional Redox Reactive Proteins and Identification...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Redox Reactive Proteins and Identification by Mass Spectrometry Results in Several Terminal Fe(III) Enrichment of Functional Redox Reactive Proteins and Identification by Mass...

  1. NNSA Authorizes Start-Up of Highly Enriched Uranium Materials...

    National Nuclear Security Administration (NNSA)

    Authorizes Start-Up of Highly Enriched Uranium Materials Facility at Y-12 | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the...

  2. US, Kazakhstan Cooperate to Eliminate Highly Enriched Uranium...

    National Nuclear Security Administration (NNSA)

    of 36 kilograms (approximately 80 pounds) of highly enriched uranium (HEU) spent fuel from the Institute of Nuclear Physics (INP) in Almaty, Kazakhstan. The HEU was...

  3. Improved Methods for the Enrichment and Analysis of Glycated...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of tissue proteins has important implications in the development of complications of diabetes mellitus. Herein we report improved methods for the enrichment and analysis of...

  4. Jefferson Lab seeks applicants for summer, science teacher enrichment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    seeks applicants for summer, science teacher enrichment program February 26, 2003 Calling all middle school teachers who instruct science classes. Jefferson Lab would like to help...

  5. News Media invited to interview JLab summer, science enrichment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2003 Education Poster Session News Media invited to interview JLab summer, science enrichment program participants; cover closing Poster Session July 28, 2004 Newport News, VA. -...

  6. Jefferson Lab Seeks Applicants for Science Teacher Enrichment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Seeks Applicants for Science Teacher Enrichment Program March 14, 2001 Calling all middle school teachers who instruct science classes. Jefferson Lab would like to help you refresh...

  7. The Chemical Enrichment History of the Magellanic Clouds Field Populations

    E-Print Network [OSTI]

    R. Carrera; C. Gallart; A. Aparicio; E. Costa; E. Hardy; R. A. Mendez; N. E. D. Noel; R. Zinn

    2008-09-24T23:59:59.000Z

    We report the results of our project devoted to study the chemical enrichment history of the field population in the Magellanic Clouds using Ca II triplet spectroscopy.

  8. Uranium enrichment decontamination and decommissioning fund

    SciTech Connect (OSTI)

    NONE

    1994-12-31T23:59:59.000Z

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

  9. DEVELOPMENT OF MORE-EFFICIENT GAS FLOODING APPLICABLE TO SHALLOW RESERVOIRS

    SciTech Connect (OSTI)

    William R. Rossen; Russell T. Johns; Gary A. Pope

    2003-08-21T23:59:59.000Z

    The objective of this research is to widen the applicability of gas flooding to shallow oil reservoirs by reducing the pressure required for miscibility using gas enrichment and increasing sweep efficiency with foam. Task 1 examines the potential for improved oil recovery with enriched gases. Subtask 1.1 examines the effect of dispersion processes on oil recovery and the extent of enrichment needed in the presence of dispersion. Subtask 1.2 develops a fast, efficient method to predict the extent of enrichment needed for crude oils at a given pressure. Task 2 develops improved foam processes to increase sweep efficiency in gas flooding. Subtask 2.1 comprises mechanistic experimental studies of foams with N2 gas. Subtask 2.2 conducts experiments with CO{sub 2} foam. Subtask 2.3 develops and applies a simulator for foam processes in field application.

  10. Adsorptive method for the separation of a gas mixture

    SciTech Connect (OSTI)

    Linde, G.

    1984-05-15T23:59:59.000Z

    A method of recovering at least two product fractions each highly enriched in a respective component of a gas mixture containing at least such components are recovered by separating a stream of the mixture into at least two partial streams and passing this stream separately through respective beds of respective adsorbents and selectively retaining at least one component from each mixture so that the respective product fractions emerge from the adsorbents highly enriched in respective components of this mixture, each adsorbent for a particular one of the fractions has a composition that retains at least one component in which the other fractions is enriched.

  11. Hot gas path analysis and data evaluation of the performance parameters of a gas turbine

    E-Print Network [OSTI]

    Hanawa, David Allen

    1974-01-01T23:59:59.000Z

    VITA 83 LIST OF FIGURES F g. 1. 1 Centrifugal Compressor Performance Nap 1. 2 Compressor and Turbine Shaft Assembly ? ag'e 1. 3 Axial Compressor Performance Nap 2. 1 Variation of Compressor Pressure Ratio Over the Load Range 2. 2 Variation... of Compressor Pressure Ratio With the Flow Rate 13 2. 3 T-s Diagram of Brayton Cycle 2. 4 Sketch of Open Cycle Gas Turbine 1 7 2. 5 Specific Heat versus Temperature 18 2. 6 Optimum Cycle Efficiency by Pressure Ratios . . . . 20 3. 1 Different Compressor...

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

    SciTech Connect (OSTI)

    NONE

    1995-07-05T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    NONE

    1995-07-05T23:59:59.000Z

    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.

  14. Advanced industrial gas turbine technology readiness demonstration program. Phase II. Final report: compressor rig fabrication assembly and test

    SciTech Connect (OSTI)

    Schweitzer, J. K.; Smith, J. D.

    1981-03-01T23:59:59.000Z

    The results of a component technology demonstration program to fabricate, assemble and test an advanced axial/centrifugal compressor are presented. This work was conducted to demonstrate the utilization of advanced aircraft gas turbine cooling and high pressure compressor technology to improve the performance and reliability of future industrial gas turbines. Specific objectives of the compressor component testing were to demonstrate 18:1 pressure ratio on a single spool at 90% polytropic efficiency with 80% fewer airfoils as compared to current industrial gas turbine compressors. The compressor design configuration utilizes low aspect ratio/highly-loaded axial compressor blading combined with a centrifugal backend stage to achieve the 18:1 design pressure ratio in only 7 stages and 281 axial compressor airfoils. Initial testing of the compressor test rig was conducted with a vaneless centrifugal stage diffuser to allow documentation of the axial compressor performance. Peak design speed axial compressor performance demonstrated was 91.8% polytropic efficiency at 6.5:1 pressure ratio. Subsequent documentation of the combined axial/centrifugal performance with a centrifugal stage pipe diffuser resulted in the demonstration of 91.5% polytropic efficiency and 14% stall margin at the 18:1 overall compressor design pressure ratio. The demonstrated performance not only exceeded the contract performance goals, but also represents the highest known demonstrated compressor performance in this pressure ratio and flow class. The performance demonstrated is particularly significant in that it was accomplished at airfoil loading levels approximately 15% higher than that of current production engine compressor designs. The test results provide conclusive verification of the advanced low aspect ratio axial compressor and centrifugal stage technologies utilized.

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

    SciTech Connect (OSTI)

    NONE

    1995-07-05T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Michaels, E.D.

    1981-02-25T23:59:59.000Z

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

  17. Sound emission from the gas of molecular superrotors

    E-Print Network [OSTI]

    Milner, A A; Milner, V

    2015-01-01T23:59:59.000Z

    We use an optical centrifuge to deposit a controllable amount of rotational energy into dense molecular ensembles. Subsequent rotation-translation energy transfer, mediated by thermal collisions, results in the localized heating of the gas and generates strong sound wave, clearly audible to the unaided ear. For the first time, the amplitude of the sound signal is analyzed as a function of the experimentally measured rotational energy. The proportionality between the two experimental observables confirms that rotational excitation is the main source of the detected sound wave. As virtually all molecules, including the main constituents of the atmosphere, are amenable to laser spinning by the centrifuge, we anticipate this work to stimulate further development in the area of photo-acoustic control and spectroscopy.

  18. Metadata Enrichment Services for the Europeana Digital Library

    E-Print Network [OSTI]

    Sebastiani, Fabrizio

    needs, thus allowing the tool to be effectively available to the multitude (2000+) of Europeana CPs. 1 to enrich the semantics of its own MRs prior to contributing them to Europeana. Different CPs are thus provenance. We view metadata enrichment as consisting of essentially two activities: clas- sification of MRs

  19. Anisotropic Outflows and Enrichment of the Intergalactic Medium

    E-Print Network [OSTI]

    Matthew M. Pieri; Hugo Martel; Cedric Grenon

    2006-11-17T23:59:59.000Z

    We have developed an analytical model for the evolution of anisotropic galactic outflows. These outflows follow the path of least resistance, and thus travel preferentially into low-density regions, away from cosmological structures where galaxies form. We show that anisotropic outflows can significantly enrich low-density systems, while reducing the enrichment of overdense regions.

  20. CENTRIFUGAL LABTUBE FOR FULLY AUTOMATED DNA EXTRACTION & LAMP AMPLIFICATION BASED ON AN INTEGRATED, LOW-COST HEATING SYSTEM

    E-Print Network [OSTI]

    Hoehl, Melanie Margarete

    In this paper, we introduce a disposable battery-driven heating system for loop-mediated isothermal DNA amplification (LAMP) inside a centrifugally-driven DNA-extraction platform (LabTube). We demonstrate fully automated, ...

  1. Modeling of Plasma-Assisted Conversion of Liquid Ethanol into Hydrogen Enriched Syngas in the Nonequilibrium Electric Discharge Plasma-Liquid System

    E-Print Network [OSTI]

    Levko, Dmitry; Naumov, Vadim; Chernyak, Valery; Yukhymenko, Vitaly; Prysiazhnevych, Irina; Olszewski, Sergey

    2008-01-01T23:59:59.000Z

    In this work we report recent results of our experimental and theoretical studies related to plasma conversion of liquid ethanol into hydrogen-enriched syngas in the plasma-liquid system with the electric discharge in a gas channel with liquid wall using available diagnostics and numerical modeling.

  2. Suppression of the centrifugal barrier effects in the off-energy-shell neutron+$^{17}$O interaction

    E-Print Network [OSTI]

    M. Gulino; C. Spitaleri; X. D. Tang; G. L. Guardo; L. Lamia; S. Cherubini; B. Bucher; V. Burjan; M. Couder; P. Davies; R. deBoer; X. Fang; V. Z. Goldberg; Z. Hons; V. Kroha; L. Lamm; M. La Cognata; C. Li; C. Ma; J. Mrazek; A. M. Mukhamedzhanov; M. Notani; S. OBrien; R. G. Pizzone; G. G. Rapisarda; D. Roberson; M. L. Sergi; W. Tan; I. . J. Thompson; M. Wiescher

    2012-12-11T23:59:59.000Z

    The reaction $^{17}$O($n,\\alpha$)$^{14}$C was studied at energies from $E_{cm}=0$ to $E_{cm}=350$ keV using the quasi-free deuteron break-up in the three body reaction $^{17}$O$+d \\rightarrow \\alpha+ ^{14}$C$+p$, extending the Trojan Horse indirect method (THM) to neutron-induced reactions. It is found that the $^{18}$O excited state at $E^*=8.125 \\pm 0.002$ MeV observed in THM experiments is absent in the direct measurement because of its high centrifugal barrier. The angular distributions of the populated resonances have been measured for the first time. The results unambiguously indicate the ability of the THM to overcome the centrifugal barrier suppression effect and to pick out the contribution of the bare nuclear interaction.

  3. Efficiency of the centrifugally induced curvature drift instability in AGN winds

    E-Print Network [OSTI]

    Z. Osmanov

    2008-05-09T23:59:59.000Z

    For studying how the field lines are twisting nearby the light cylinder surface, which provides the free motion of AGN winds through the mentioned area, the investigation of the centrifugally driven curvature drift instability is presented. Studying the dynamics of the relativistic MHD flow close to the light cylinder surface, by applying a single particle approach based on the centrifugal acceleration, the dispersion relation of the instability is derived and analytically solved. Considering the typical values of AGN winds, it is shown that the time scale of the curvature drift instability is much less than the accretion process time scale, indicating that the present instability is very efficient and might strongly influence processes in AGN plasmas.

  4. Final Environmental Impact Statement for the construction and operation of Claiborne Enrichment Center, Homer, Louisiana (Docket No. 70-3-70). Volume 2, Public comments and NRC response

    SciTech Connect (OSTI)

    Zeitoun, A. [Science Applications International Corp., Germantown, MD (United States)

    1994-08-01T23:59:59.000Z

    The Final Environmental Impact Statement (FEIS) (Volume 1), was prepared by the Nuclear Regulatory Commission (NRC) in accordance with regulation 10 CFR Part 51, which implements the National Environmental Policy Act (NEPA), to assess the potential environmental impacts for licensing the construction and operation of a proposed gaseous centrifuge enrichment facility to be built in Claiborne Parish, Louisiana by Louisiana Energy Services, L.P. (LES). The proposed facility would have a production capacity of about 866 metric tons annually of up to 5 weight percent enriched UF{sub 6}, using a proven centrifuge technology. Included in the assessment are co on, both normal operations and potential accidents (internal and external events), and the eventual decontamination and decommissioning of the site. In order to help assure that releases from the operation of the facility and potential impacts on the public are as low as reasonably achievable, an environmental monitoring program was developed by LES to detect significant changes in the background levels of uranium around the site. Other issues addressed include the purpose and need for the facility, the alternatives to the proposed action, potential disposition of the tails, the site selection process, and environmental justice. The NRC staff concludes that the facility can be constructed and operated with small and acceptable impacts on the public and the environment, and proposes to issue a license to the applicant, Louisiana Energy Services, to authorize construction and operation of the proposed facility. The letters in this Appendix have been divided into three sections. Section One contains letters to which the NRC responded by addressing specific comments. Section Two contains the letters that concerned the communities of Forest Grove and Center Springs. Section Three is composed of letters that required no response. These letters were generally in support of the facility.

  5. A finite element model of the turbulent flow field in a centrifugal impeller

    E-Print Network [OSTI]

    Hlavaty, Steven Todd

    1993-01-01T23:59:59.000Z

    , or for applications such as pumps utilizing a liquid as the working medium. Full ellipticity of the flow- governing equations throughout the computational domain is rigorously retained. As a result, the model is conceptually capable of predicting real-flow effects... such as flow separation and recirculation, regardless of whether such complex flow behavior is local or massive. Applicability of the model is illustrated using a typical pump impeller of the purely centrifugal type. In presenting the computed flow field...

  6. Centrifuge modeling of radioactive waste migration through backfill in a near surface disposal facility

    SciTech Connect (OSTI)

    Gurumoorthy, C.; Kusakabe, O. [Geotechnical Engineering Division, Tokyo Institute of Technology, 2-12-1 Ookayama Meguroku, Tokyo 1528552 (Japan)

    2007-07-01T23:59:59.000Z

    Investigations on the performance of backfill barrier in Near Surface Disposal Facility (NSDF) for radioactive wastes are important to ensure the long term safety of such disposal option. Favorable condition to delay migration of radionuclides from disposed waste to far fields is diffusion process. However, advective dispersion/diffusion mechanism plays an important role due to changes in backfill over a period of time. In order to understand these mechanisms, detailed laboratory experiments are usually conducted for developing mathematical models to assess the behaviour of backfill. However, these experiments are time consuming and suffer with the limitations due to material complexity. Also, there are constraints associated with validation of theoretical predictions due to intricacy of boundary conditions as well as the time scale is quite different as compared to the time required for completion of the processes in the field. Keeping in view these aspects, centrifuge modeling technique has been adopted by various researchers to model and understand various geo-environment problems in order to provide a link between the real life situation termed as the 'Prototype' and its model, which is exposed to a higher gravitational field. An attempt has been made in this paper to investigate the feasibility of this technique to model advective dispersion/diffusion mechanism of radionuclides through saturated Bentonite-Sand (B:S) backfill. Various stages of centrifuge modeling are highlighted. Column tests were conducted in the centrifuge to evaluate the hydraulic conductivity of B:S mixture under prototype NSDF stress conditions. Results showed that steady state hydraulic conductivity under saturated conditions was 2.86 10{sup -11} m/sec. Studies indicate the feasibility of centrifuge modeling technique and usefulness to model advective diffusion of radionuclides through B:S backfill. (authors)

  7. Free Air CO2 Enrichment (FACE) Data from the Duke Forest FACE Facility

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    DOE has conducted trace gas enrichment experiments since the mid 1990s. The FACE Data Management System is a central repository and archive for Free-Air Carbon Dioxide Enrichment (FACE) data, as well as for the related open-top chamber (OTC) experiments. FACE Data Management System is located at DOEĆs Carbon Dioxide Information Analysis Center (CDIAC). While the data from the various FACE sites, each one a unique user facility, are centralized at CDIAC, each of the FACE sites presents its own view of its activities and information. For that reason, DOE Data Explorer users are advised to see both the central repository at http://public.ornl.gov/face/index.shtml and the individual home pages of each site. The Duke University FACE website actually presents information on several FACE experiments. The Forest-Atmosphere Carbon Transfer and Storage (FACTS-I) facility is located in the Blackwood Division of the Duke Forest. It consists of four free-air CO2 enrichment (FACE) plots that provide elevated atmospheric CO2 concentration and four plots that provide ambient CO2 control. The system has been in operation since June, 1994 in the prototype plot, and since August, 1996 in the three additional plots. The prototype plot and its reference were halved with a barrier inserted in the soil in 1998 to conduct, together with five additional plot pairs, CO2 X soil nutrient enrichment experiments. The rest of the plots were partitioned in early 2005 and incorporated into the CO2 X nutrient experiment. To increase statistical power, four additional ambient plots were established in January, 2005, halved, and one half of each fertilized. [copied from http://face.env.duke.edu/description.cfm] The Duke FACE home page makes information available from both completed and ongoing projects, provides a searchable database of publications and presentations, and data, images, and links to related websites.

  8. Correction of Wall Adhesion Effects in the Centrifugal Compression of Strong Colloidal Gels

    E-Print Network [OSTI]

    Richard Buscall; Daniel R. Lester

    2014-10-09T23:59:59.000Z

    Several methods for measuring the compressive strength of strong particulate gels are available, including the centrifuge method, whereby the strength as a function of volume-fraction is obtained parametrically from the dependence of equilibrium sediment height upon acceleration. The analysis used conventionally due to Buscall & White (1987) ignores the possibility that the particulate network might adhere to the walls of the centrifuge tube, even though many types of cohesive particulate gel can be expected to. The neglect of adhesion is justifiable when the ratio of the shear to compressive strength is small, which it can be for many systems away from the gel-point, but never very near it. The errors arising from neglect of adhesion are investigated theoretically and quantified by synthesising equilibrium sediment height versus acceleration data for various degrees of adhesion and then analysing them in the conventional manner. Approximate correction factors suggested by dimensionless analysis are then tested. The errors introduced by certain other approximations made routinely in order to render the data-inversion practicable are analysed too. For example, it shown that the error introduced by treating the acceleration vector as approximately one-dimensional is minuscule for typical centrifuge dimensions, whereas making this assumption renders the data inversion tractable.

  9. Acoustic oscillations of rapidly rotating polytropic stars. II. Effects of the Coriolis and centrifugal accelerations

    E-Print Network [OSTI]

    D. Reese; F. Ligničres; M. Rieutord

    2006-09-26T23:59:59.000Z

    Context: With the launch of space missions devoted to asteroseismology (like COROT), the scientific community will soon have accurate measurements of pulsation frequencies in many rapidly rotating stars. Aims: The present work focuses on the effects of rotation on pulsations of rapidly rotating stars when both the Coriolis and centrifugal accelerations require a non-perturbative treatment. Method: We develop a 2-dimensional spectral numerical approach which allows us to compute acoustic modes in centrifugally distorted polytropes including the full influence of the Coriolis force. This method is validated through comparisons with previous studies, and the results are shown to be highly accurate. Results: In the frequency range considered and with COROT's accuracy, we establish a domain of validity for perturbative methods, thus showing the need for complete calculations beyond v.sin i = 50 km/s for a R = 2.3 R_\\odot, M = 1.9 M_\\odot polytropic star. Furthermore, it is shown that the main differences between complete and perturbative calculations come essentially from the centrifugal distortion.

  10. Compton DIV: Using a Compton-Based Gamma-Ray Imager for Design Information Verification of Uranium Enrichment Plants

    SciTech Connect (OSTI)

    Burks, M; Verbeke, J; Dougan, A; Wang, T; Decman, D

    2009-07-04T23:59:59.000Z

    A feasibility study has been performed to determine the potential usefulness of Compton imaging as a tool for design information verification (DIV) of uranium enrichment plants. Compton imaging is a method of gamma-ray imaging capable of imaging with a 360-degree field of view over a broad range of energies. These systems can image a room (with a time span on the order of one hour) and return a picture of the distribution and composition of radioactive material in that room. The effectiveness of Compton imaging depends on the sensitivity and resolution of the instrument as well the strength and energy of the radioactive material to be imaged. This study combined measurements and simulations to examine the specific issue of UF{sub 6} gas flow in pipes, at various enrichment levels, as well as hold-up resulting from the accumulation of enriched material in those pipes. It was found that current generation imagers could image pipes carrying UF{sub 6} in less than one hour at moderate to high enrichment. Pipes with low enriched gas would require more time. It was also found that hold-up was more amenable to this technique and could be imaged in gram quantities in a fraction of an hour. another questions arises regarding the ability to separately image two pipes spaced closely together. This depends on the capabilities of the instrument in question. These results are described in detail. In addition, suggestions are given as to how to develop Compton imaging as a tool for DIV.

  11. ORIGIN OF LITHIUM ENRICHMENT IN K GIANTS

    SciTech Connect (OSTI)

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

    2011-03-20T23:59:59.000Z

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

  12. Saturn's internal structure and carbon enrichment

    E-Print Network [OSTI]

    Olivier Mousis; Yann Alibert; Willy Benz

    2005-11-14T23:59:59.000Z

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

  13. Linking the Metallicity Distribution of Galactic Halo Stars to the Enrichment History of the Universe

    E-Print Network [OSTI]

    Evan Scannapieco; Tom Broadhurst

    2001-02-06T23:59:59.000Z

    We compare the metallicity distribution of Galactic Halo stars with 3D realizations of hierarchical galaxy formation. Outflows from dwarf galaxies enrich the intergalactic medium inhomogeneously, at a rate depending on the local galaxy density. Consequently, the first stars created in small early-forming galaxies are less metal-rich that the first stars formed in more massive galaxies which typically form later. As most halo stars are likely to originate in accreted dwarfs, while disk stars formed out of outflow-enriched gas, this scenario naturally generates a ``metallicity floor'' for old disk stars, which we find to be roughly coincident with the higher end of our predicted metallicity distribution of halo stars, in agreement with observations. The broad and centrally peaked distribution of halo star metallicities is well reproduced in our models, with a natural dispersion depending on the exact accretion history. Our modeling includes the important ``baryonic stripping'' effect of early outflows, which brush away the tenuously held gas in neighboring pre-virialized density perturbations. This stripping process does not significantly modify the predicted shape of the halo star metal distribution but inhibits star-formation and hence the number of accreted stars, helping to reproduce the observed total Galactic halo luminosity and also the lack of low-luminosity local dwarf galaxies relative to N-body predictions.

  14. Enrichment Assay Methods for a UF6 Cylinder Verification Station

    SciTech Connect (OSTI)

    Smith, Leon E.; Jordan, David V.; Misner, Alex C.; Mace, Emily K.; Orton, Christopher R.

    2010-11-30T23:59:59.000Z

    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 cylinder inventory. These enrichment assay methods interrogate only a small fraction of the total cylinder volume, and are time-consuming and expensive to execute for inspectors. Pacific Northwest National Laboratory (PNNL) is developing an unattended measurement system capable of automated enrichment measurements over the full volume of Type 30B and Type 48 cylinders. This 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 focus of this paper is the development of nondestructive assay (NDA) methods that combine “traditional” enrichment signatures (e.g. 185-keV emission from U-235) and more-penetrating “non-traditional” signatures (e.g. high-energy neutron-induced gamma rays spawned primarily from U-234 alpha emission) collected by medium-resolution gamma-ray spectrometers (i.e. sodium iodide or lanthanum bromide). The potential of these NDA methods for the automated assay of feed, tail and product cylinders is explored through MCNP modeling and with field measurements on a cylinder population ranging from 0.2% to 5% in U-235 enrichment.

  15. Trophic ecology of the invasive argentine ant: spatio-temporal variation in resource assimilation and isotopic enrichment

    E-Print Network [OSTI]

    Menke, Sean B.; Suarez, Andy V.; Tillberg, Chadwick V.; Chou, Cheng T.; Holway, David A.

    2010-01-01T23:59:59.000Z

    assimilation and isotopic enrichment Sean B. Menke • Andy V.determined nitrogen enrichment using a controlled laboratoryconsumer- diet d15N enrichment: a meta-analysis. Oecologia

  16. Near-surface enrichment of zooplankton over a shallow back reef: implications for coral reef food webs

    E-Print Network [OSTI]

    Alldredge, A. L.; King, J. M.

    2009-01-01T23:59:59.000Z

    0534-4 REPORT Near-surface enrichment of zooplankton over anear the bottom but no enrichment aloft. In Moorea, whereand mixing, zooplankton enrichment extended throughout the

  17. Cognitive Research with Dolphins (Tursiops truncatus) at Disney’s The Seas: A Program for Enrichment, Science, Education, and Conservation

    E-Print Network [OSTI]

    Harley, Heidi E.; Fellner, Wendi; Stamper, M. Andy

    2010-01-01T23:59:59.000Z

    Second nature: Environmental enrichment for captive animals.The Seas: A Program for Enrichment, Science, Education, andin four main areas: enrichment, science, education, and

  18. Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design

    E-Print Network [OSTI]

    , Gamma Spectrometry, uranium enrichment #12;PAPER Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design Gamma spectroscopy is commonly used in nuclear safeguards to measure uranium enrichment. An experimental

  19. Method and apparatus for manufacturing gas tags

    DOE Patents [OSTI]

    Gross, Kenny C. (Bolingbrook, IL); Laug, Matthew T. (Idaho Falls, ID)

    1996-01-01T23:59:59.000Z

    For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection. For a tag blending process involving M tag isotopes with N distinct feed gas mixtures commercially available from an enriched gas supplier, the manufacturing process calculates the cost difference between multiple combinations and specifies gas mixtures which approach the optimum defined conditions. The manufacturing process is then used to control tag blending apparatus incorporating tag gas canisters connected by stainless-steel tubing with computer controlled valves, with the canisters automatically filled with metered quantities of the required feed gases.

  20. Method and apparatus for manufacturing gas tags

    DOE Patents [OSTI]

    Gross, K.C.; Laug, M.T.

    1996-12-17T23:59:59.000Z

    For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection. For a tag blending process involving M tag isotopes with N distinct feed gas mixtures commercially available from an enriched gas supplier, the manufacturing process calculates the cost difference between multiple combinations and specifies gas mixtures which approach the optimum defined conditions. The manufacturing process is then used to control tag blending apparatus incorporating tag gas canisters connected by stainless-steel tubing with computer controlled valves, with the canisters automatically filled with metered quantities of the required feed gases. 4 figs.

  1. Resin-assisted Enrichment of N-terminal Peptides for Characterizing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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

  2. Enriched Background Isotope Study (EBIS) Litter reciprocal transplant studies to understand sources, transport and

    E-Print Network [OSTI]

    1 Enriched Background Isotope Study (EBIS) Litter reciprocal transplant studies to understand were removed from this archived version.] #12;3 Enriched Background Isotope Study (EBIS): Litter

  3. Glycomimetic affinity-enrichment proteomics identifies partners for a clinically-utilized iminosugar

    E-Print Network [OSTI]

    Davis, Ben G.

    Glycomimetic affinity-enrichment proteomics identifies partners for a clinically and utilize a natural product-derived glycomimetic iminosugar probe in a Glycomimetic Affinity-enrichment

  4. Resin-assisted enrichment of thios as a general strategy for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    enrichment of thios as a general strategy for proteomic profiling of cysteine-based reversible modifications. Resin-assisted enrichment of thios as a general strategy for proteomic...

  5. Identification of Cross-Linked Peptides after Click-Based Enrichment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cross-Linked Peptides after Click-Based Enrichment Using Sequential Collision-Induced Dissociation and Identification of Cross-Linked Peptides after Click-Based Enrichment Using...

  6. atmospheric co2 enrichment: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Soil carbon sequestration in a pine forest after 9 years of atmospheric CO2 enrichment...

  7. air co2 enrichment: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with increasing CO2 between ambient (1.0x California at Santa Cruz, University of 13 Soil carbon sequestration in a pine forest after 9 years of atmospheric CO2 enrichment...

  8. The uranium cylinder assay system for enrichment plant safeguards

    SciTech Connect (OSTI)

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

    2010-01-01T23:59:59.000Z

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

  9. Y-12 and the Ťsuper enriched Uranium 235?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    "super enriched Uranium 235" Ken Bernander called me to say that he had read in the newspaper about the 100 milligrams of uranium oxide that is 99.999% U-235. He was chuckling when...

  10. anthropogenic uranium enrichments: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Websites Summary: Flats Plutonium and Uranium Weapons-Grade Plutonium Enriched Uranium Depleted Uranium Plutonium-238 0.01 - 0.05% Uranium-234 0.1 - 1.02% Uranium-234...

  11. A fast enriched FEM for Poisson equations involving interfaces

    E-Print Network [OSTI]

    Huynh, Thanh Le Ngoc

    2008-01-01T23:59:59.000Z

    We develop a fast enriched finite element method for solving Poisson equations involving complex geometry interfaces by using regular Cartesian grids. The presence of interfaces is accounted for by developing suitable jump ...

  12. Self-enrichment of Galactic halo globular clusters: stimulated star formation and consequences for the halo metallicity distribution

    E-Print Network [OSTI]

    Genevieve Parmentier

    2004-03-10T23:59:59.000Z

    We explore the self-enrichment hypothesis for globular cluster formation with respect to the star formation aspect. Following this scenario, the massive stars of a first stellar generation chemically enrich the globular progenitor cloud up to Galactic halo metallicities and sweep it into an expanding spherical shell of gas. This paper investigates the ability of this swept proto-globular cloud to become gravitationally unstable and, therefore, to seed the formation of second generation stars which may later on form a globular cluster. We use a simple model based on a linear perturbation theory for transverse motions in a shell of gas to demonstrate that the pressures by which the progenitor clouds are bound and the supernova numbers required to achieve Galactic halo metallicities support the successful development of the shell transverse collapse. Interestingly, the two parameters controling the metallicity achieved through self-enrichment, namely the number of supernovae and the external pressure, also rule the surface density of the shell and thus its ability to undergo a transverse collapse. Such a supernova-induced origin for the globular cluster stars opens therefore the way to the understanding of the halo metallicity distributions. This model is also able to explain the lower limit of the halo globular cluster metallicity.

  13. A direct method for determining complete positive and negative capillary pressure curves for reservoir rock using the centrifuge

    SciTech Connect (OSTI)

    Spinler, E.A.; Baldwin, B.A. [Phillips Petroleum Co., Bartlesville, OK (United States)

    1997-08-01T23:59:59.000Z

    A method is being developed for direct experimental determination of capillary pressure curves from saturation distributions produced during centrifuging fluids in a rock plug. A free water level is positioned along the length of the plugs to enable simultaneous determination of both positive and negative capillary pressures. Octadecane as the oil phase is solidified by temperature reduction while centrifuging to prevent fluid redistribution upon removal from the centrifuge. The water saturation is then measured via magnetic resonance imaging. The saturation profile within the plug and the calculation of pressures for each point of the saturation profile allows for a complete capillary pressure curve to be determined from one experiment. Centrifuging under oil with a free water level into a 100 percent water saturated plug results in the development of a primary drainage capillary pressure curve. Centrifuging similarly at an initial water saturation in the plug results in the development of an imbibition capillary pressure curve. Examples of these measurements are presented for Berea sandstone and chalk rocks.

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

    E-Print Network [OSTI]

    McCord, Cameron (Cameron Liam)

    2014-01-01T23:59:59.000Z

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

  15. Effects of friction factor and slip factor on the performance of a centrifugal slurry pump 

    E-Print Network [OSTI]

    Sheth, Ketankumar Kantilal

    1985-01-01T23:59:59.000Z

    , mass, or volume flow. 3. 2. 4 Recirculating Pump small centrifugal pump (Figure 9) was used to keep the slurry agitating within the tank by discharging in the Q w, pg+p~w '=A ~ fl p rr f f+4;. '"2 '. . . &f -. P'. . !' ' g- ' ?y 25 bottom... elbow hav ing pressure taps 0 at 45 as shown in figure 10 was used for a flowmeter. Two 1/8" diameter holes were drilled on the inner and outer side of the elbow and 1/8" diameter pipe nipples were welded for pressure transducer connection. 3. 2. 6...

  16. Laser velocimetry study of the flow field in a centrifugal pump

    E-Print Network [OSTI]

    Rashid, Kazi M.

    1993-01-01T23:59:59.000Z

    ~ I 0 ((I (K IE 0 Eg g 0 :5 8 O 0 g E( (((E QO . . E- 6i EEE 5!X. . ( N CC E(: NI RS KR OQ 0 EEW AA 0 -"ni V 0 O CO (EP 4 EEE 0 ~ E Q Og ((E O ~ 0(O A 00 ~ 0 E' ~ 29 the beam splitter prism. The direction of the flow...-Chair of Committee) PS4~ Yassin A. Hassan (Member) W. L. Bradley (Head of Department) MAY 1993 ABSTRACT Laser Velocimetry Study of the Flow Field in a Centrifugal Pump. (May 1993) Kazi M. Rashid, B. S. , Bangladesh University of Engineering & Technology Co...

  17. Processing liquid radioactive waste by centrifuge and indrum dehydration facility at NPP Philippsburg

    SciTech Connect (OSTI)

    Grundke, E.; Blaser, W. [NPP Philippsburg (Germany)

    1993-12-31T23:59:59.000Z

    Until 1989 the evaporator and filter concentrates have been treated by concreting. The centrifuge facility is used for the liquid waste from laundry, showers and also for processing filter concentrates and evaporator feedwater. The hot high pressure compacting of filter concentrates gives a volume reduction by a factor of 6. The evaporator concentrate is drained in a 200 l drum and this drum is heated by an external heating device. The indrum-dehydration facility reduces the treated volume by a factor of 12 compared with the former cementation.

  18. EIS-0468: American Centrifuge Plant in Piketon, OH | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised FindingDepartmentDepartment of Energy Notice8: American Centrifuge

  19. Method and apparatus for automated processing and aliquoting of whole blood samples for analysis in a centrifugal fast analyzer

    DOE Patents [OSTI]

    Burtis, C.A.; Johnson, W.F.; Walker, W.A.

    1985-08-05T23:59:59.000Z

    A rotor and disc assembly for use in a centrifugal fast analyzer. The assembly is designed to process multiple samples of whole blood followed by aliquoting of the resultant serum into precisely measured samples for subsequent chemical analysis. The assembly requires minimal operator involvement with no mechanical pipetting. The system comprises: (1) a whole blood sample disc; (2) a serum sample disc; (3) a sample preparation rotor; and (4) an analytical rotor. The blood sample disc and serum sample disc are designed with a plurality of precision bore capillary tubes arranged in a spoked array. Samples of blood are loaded into the blood sample disc by capillary action and centrifugally discharged into cavities of the sample preparation rotor where separation of serum and solids is accomplished. The serum is loaded into the capillaries of the serum sample disc by capillary action and subsequently centrifugally expelled into cuvettes of the analyticaly rotor for conventional methods. 5 figs.

  20. Method and apparatus for automated processing and aliquoting of whole blood samples for analysis in a centrifugal fast analyzer

    DOE Patents [OSTI]

    Burtis, Carl A. (Oak Ridge, TN); Johnson, Wayne F. (Loudon, TN); Walker, William A. (Knoxville, TN)

    1988-01-01T23:59:59.000Z

    A rotor and disc assembly for use in a centrifugal fast analyzer. The assembly is designed to process multiple samples of whole blood followed by aliquoting of the resultant serum into precisely measured samples for subsequent chemical analysis. The assembly requires minimal operator involvement with no mechanical pipetting. The system comprises (1) a whole blood sample disc, (2) a serum sample disc, (3) a sample preparation rotor, and (4) an analytical rotor. The blood sample disc and serum sample disc are designed with a plurality of precision bore capillary tubes arranged in a spoked array. Samples of blood are loaded into the blood sample disc in capillary tubes filled by capillary action and centrifugally discharged into cavities of the sample preparation rotor where separation of serum and solids is accomplished. The serum is loaded into the capillaries of the serum sample disc by capillary action and subsequently centrifugally expelled into cuvettes of the analytical rotor for analysis by conventional methods.

  1. Generalized Modeling of Enrichment Cascades That Include Minor Isotopes

    SciTech Connect (OSTI)

    Weber, Charles F [ORNL

    2012-01-01T23:59:59.000Z

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

  2. Free Air CO2 Enrichment (FACE) Research Data from the Nevada Desert FACE Facility (NDFF)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    DOE has conducted trace gas enrichment experiments since the mid 1990s. The FACE Data Management System is a central repository and archive for Free-Air Carbon Dioxide Enrichment (FACE) data, as well as for the related open-top chamber (OTC) experiments. FACE Data Management System is located at the Carbon Dioxide Information Analysis Center (CDIAC). While the data from the various FACE sites, each one a unique user facility, are centralized at CDIAC, each of the FACE sites presents its own view of its activities and information. For that reason, DOE Data Explorer users are advised to see both the central repository at http://public.ornl.gov/face/index.shtml and the individual home pages of each site. NDFF whole-ecosystem manipulation is a flagship experiment of the Terrestrial Carbon Process (TCP) research program of the US Dept. of Energy. It is also a core project of the International Geosphere-Biosphere Program (IGBP) and a contribution to the US Global Change Research Program. The NDFF was developed in conjunction with the National Science Foundation (NSF) and DOE-EPSCoR programs. FACE (Free-Air-Carbon dioxide-Enrichment) technology allows researchers to elevate the carbon dioxide level in large study plots while minimizing ecosystem disturbance. At the NDFF the concentration of CO2 was elevated by 50 percent above the present atmospheric levels in three plots in the Mojave Desert ecosystem, while six other plots remained at the current level. This experimental design provided a large area in which integrated teams of scientists could describe and quantify processes regulating carbon, nutrient, and water balances in desert ecosystems.

  3. Oxidative weathering chemical migration under variably saturated conditions and supergene copper enrichment

    SciTech Connect (OSTI)

    Xu, Tianfu; Pruess, K.; Brimhall, G.

    1999-04-01T23:59:59.000Z

    Transport of oxygen gas from the land surface through an unsaturated zone has a strong influence on oxidative weathering processes. Oxidation of sulfide minerals such as pyrite (FeS{sub 2}), one of the most common naturally occurring minerals, is the primary source of acid drainage from mines and waste rock piles. Here we present a detailed numerical model of supergene copper enrichment that involves the oxidative weathering of pyrite (FeS{sub 2}) and chalcopyrite (CuFeS{sub 2}), and acidification that causes mobilization of metals in the unsaturated zone, with subsequent formation of enriched ore deposits of chalcocite (CuS) and covellite (Cu{sub 2}S) in the reducing conditions below the water table. We examine and identify some significant conceptual and computational issues regarding the oxidative weathering processes through the modeling tool. The dissolution of gaseous oxygen induced by the oxidation reduces oxygen partial pressure, as well as the total pressure of the gas phase. As a result, the gas flow is modified, then the liquid phase flow. Results indicate that this reaction effect on the fluid flow may not be important under ambient conditions, and gas diffusion can be a more important mechanism for oxygen supply than gas or liquid advection. Acidification, mobilization of metals, and alteration of primary minerals mostly take place in unsaturated zone (oxidizing), while precipitation of secondary minerals mainly occurs in saturated zone (reducing). The water table may be considered as an interface between oxidizing and reducing zones. Moving water table due to change of infiltration results in moving oxidizing zone and redistributing aqueous chemical constitutes and secondary mineral deposits. The oxidative weathering processes are difficult to model numerically, because concentrations of redox sensitive chemical species such as O{sub 2}(aq), SO{sub 4}{sup 2-} and HS{sup -} may change over tens of orders of magnitude between oxidizing and reducing conditions. In order to simulate substantial reaction progress over geologic time, one can benefit from the quasi-stationary state (QSS) approximation. A significant saving of computing time using QSS is demonstrated through the example. In addition, changes in porosity and permeability due to mineral dissolution and precipitation are also addressed in some degree. Even though oxidative weathering is sensitive to many factors, this work demonstrates that our model provides a comprehensive suite of process modeling capabilities, which could serve as a prototype for oxidative weathering processes with broad significance for geoscientific, engineering, and environmental applications.

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

    E-Print Network [OSTI]

    Kushner, Mark

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

  5. High-solids enrichment of thermophilic microbial communities and their enzymes on bioenergy feedstocks

    E-Print Network [OSTI]

    Reddy, A. P.

    2012-01-01T23:59:59.000Z

    strain isolated from black liquor. Bioresource Technologyhave been enriched in black liquor samples from paper

  6. Origin of enriched ocean ridge basalts and implications for mantle dynamics

    E-Print Network [OSTI]

    Langmuir, Charles H.

    Origin of enriched ocean ridge basalts and implications for mantle dynamics Kathleen E. Donnellya that a small proportion of basalt are enriched in incompatible elements (enriched mid-ocean ridge basalts, E-MORB) from the MARK area. It is apparent that enriched magma sources, not associated with hot spots

  7. How Enrichment Affects Exploration Trade-Offs in Rats: Implications for Welfare and Well-Being

    E-Print Network [OSTI]

    Champagne, Frances A.

    How Enrichment Affects Exploration Trade-Offs in Rats: Implications for Welfare and Well-being and animal welfare, we designed a novel test of exploration behavior. Environmentally and socially enriched, 20 animals remained in enriched housing (enrichment-maintenance) while 40 animals were re

  8. Evaluation of Dynamic Behavior of Pile Foundations for Interim Storage Facilities Through Geotechnical Centrifuge Tests

    SciTech Connect (OSTI)

    Shizuo Tsurumaki [Nuclear Power Engineering Corporation, Fujitakanko Toranomon Bldg. 7F, 3-17-1 Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Hiroyuki Watanabe [Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Akira Tateishi; Kenichi Horikoshi; Shunichi Suzuki [Taisei Corporation, 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-0606 (Japan)

    2002-07-01T23:59:59.000Z

    In Japan, there is a possibility that interim storage facilities for recycled nuclear fuel resources may be constructed on quaternary layers, rather than on hard rock. In such a case, the storage facilities need to be supported by pile foundations or spread foundations to meet the required safety level. The authors have conducted a series of experimental studies on the dynamic behavior of storage facilities supported by pile foundations. A centrifuge modeling technique was used to satisfy the required similitude between the reduced size model and the prototype. The centrifuge allows a high confining stress level equivalent to prototype deep soils to be generated (which is considered necessary for examining complex pile-soil interactions) as the soil strength and the deformation are highly dependent on the confining stress. The soil conditions were set at as experimental variables, and the results are compared. Since 2000, the Nuclear Power Engineering Corporation (NUPEC) has been conducting these research tests under the auspices on the Ministry of Economy, Trade and Industry of Japan. (authors)

  9. Superintegrability on N-dimensional curved spaces: Central potentials, centrifugal terms and monopoles

    E-Print Network [OSTI]

    Angel Ballesteros; Alberto Enciso; Francisco J. Herranz; Orlando Ragnisco

    2008-12-10T23:59:59.000Z

    The N-dimensional Hamiltonian H formed by a curved kinetic term (depending on a function f), a central potential (depending on a function U), a Dirac monopole term, and N centrifugal terms is shown to be quasi-maximally superintegrable for any choice of the functions f and U. This result is proven by making use of the underlying sl(2,R)-coalgebra symmetry of H in order to obtain a set of (2N-3) functionally independent integrals of the motion, that are explicitly given. Such constants of the motion are "universal" since all of them are independent of both f and U. This Hamiltonian describes the motion of a particle on any ND spherically symmetric curved space (whose metric is specified by a function f) under the action of an arbitrary central potental U, and includes simultaneously a monopole-type contribution together with N centrifugal terms that break the spherical symmetry. Moreover, we show that two appropriate choices for U provide the "intrinsic" oscillator and the KC potentials on these curved manifolds. As a byproduct, the MIC-Kepler, the Taub-NUT and the so called multifold Kepler systems are shown to belong to this class of superintegrable Hamiltonians, and new generalizations thereof are obtained. The Kepler and oscillator potentials on N-dimensional generalizations of the four Darboux surfaces are discussed as well.

  10. 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 (OSTI)

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

    2008-01-01T23:59:59.000Z

    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.

  11. A three-phase centrifuge to minimize waste from production tank bottoms and sludges: An economic analysis

    SciTech Connect (OSTI)

    Polston, C.E.; Parkinson, W.J.; Graham, A.L.; Steele, R.D. [Los Alamos National Lab., NM (United States); Bretz, R.E. [New Mexico Tech., Albuquerque, NM (United States)

    1995-03-01T23:59:59.000Z

    The performance of a three-phase centrifuge process in separating tank bottoms into salable oil, brine and solids was scaled using the sigma method. The profitability was analyzed for a range of processed volumes for three business scenarios: producer owned, service company and a disposal facility. Centrifuge processes operated at full capacity in these situations may be very profitable investments but any investment decision should be heavily influenced by the annual volume to be processed, the quality of the feed and the price received for separated oil.

  12. Bus application of oxygen-enrichment technology and diesel-electric hybrid systems

    SciTech Connect (OSTI)

    Sekar, R.R.; Marr, W.W.

    1993-10-01T23:59:59.000Z

    The amendments to the Clean Air Act (CAA) mandate very strict limits on particulate, smoke, and other emissions from city buses. The use of alternative fuels, such as compressed natural gas (CNG) or methanol, can help transit operators, such as the Chicago Transit Authority (CTA), meet the mandated limits. However, the capital investment needed to convert the fueling infrastructure and buses is large, as is the expense of training personnel. If a {open_quotes}clean diesel{close_quotes} bus can be implemented with the help of oxygen-enrichment technology or a diesel-electric hybrid system, this large investment could be postponed for many years. The Regional Transportation Authority (RTA) initiated this project to evaluate the possibility of applying these technologies to CTA buses. Argonne National Laboratory (ANL) conducted a limited number of engine tests and computer analyses and concluded that both concepts are practical and will help in a {open_quotes}clean diesel{close_quotes} bus that can meet the mandated limits of the CAA amendments. The oxygen enrichment of combustion air depends on the availability of a compact and economical membrane separator. Because the technology for this critical component is still under development, it is recommended that an actual bus demonstration be delayed until prototype membranes are available. The hybrid propulsion system is ready for the demonstration phase, and it is recommended that the CTA and RTA commence planning for a bus demonstration.

  13. The Enrichment of Intergalactic Medium With Adiabatic Feedback I: Metal Cooling and Metal Diffusion

    E-Print Network [OSTI]

    Shen, Sijing; Stinson, Gregory

    2009-01-01T23:59:59.000Z

    A study of IGM metal enrichment using a series of SPH simulations is presented, employing metal cooling and the turbulent diffusion of metals and thermal energy. Stellar feedback naturally drives winds in the simulations reproducing both the observed star formation history (SFH) and the universal neutral hydrogen fraction. This challenges assumptions that wind recipes are necessary for correct SFH. The mass and metal evolution in stars and various gas phases was investigated. At z=0, 40 % of the baryons are in the warm-hot intergalactic medium (WHIM), but most metals (82 %) are in stars. At higher z the most metals were in the IGM was higher due to more efficient winds. This indicates that IGM metals primarily reside in the WHIM throughout cosmic history (unlike momentum driven wind model). The WHIM metallicity is 0.01-0.1 solar with a slight decrease at lower z. The metallicity evolution is consistent with observations. Galactic winds most efficiently enrich the IGM for intermediate mass galaxies ($10^{10}$M...

  14. Chemical Enrichment at High Redshifts: Understanding the Nature of Damped Ly$?$ Systems in Hierarchical Models

    E-Print Network [OSTI]

    P. B. Tissera; D. G. Lambas M. B. Mosconi; S. A. Cora

    2001-04-18T23:59:59.000Z

    We use cosmological hydrodynamical simulations including star formation and metal enrichment to study the evolution of the chemical properties of galaxy-like objects at high redshift in the range $0.25Hydrogen column densities with abundances and scatter comparable to those observed in damped Lyman-$\\alpha$ systems (DLAs).The unweighted mean of abundance ratios and least square linear regressions through the simulated DLAs yield intrinsic metallicity evolution for the [Zn/H] and [Fe/H], consistent with results obtained from similar analysis of available observations. Our model statistically reproduces the mild evolution detected in the metallicity of the neutral hydrogen content of the Universe, given by mass-weighted means,if observational constraints are considered (as suggested by Boiss\\'ee et al. 1998). For the $\\alpha$-elements in the simulated DLAs, we find neither enhancement nor dependence on metallicity. Our results support the hypotheses that DLAs trace a variety of galactic objects with different formation histories and that both SNI and SNII are contributing to the chemical enrichment of the gas component at least since $z \\approx 2$. This study indicates that DLAs could be understood as the building blocks that merged to form today normal galaxies within a hierarchical clustering scenario.

  15. Compact reaction cell for homogenizing and down-blending highly enriched uranium metal

    DOE Patents [OSTI]

    McLean, W. II; Miller, P.E.; Horton, J.A.

    1995-05-02T23:59:59.000Z

    The invention is a specialized reaction cell for converting uranium metal to uranium oxide. In a preferred form, the reaction cell comprises a reaction chamber with increasing diameter along its length (e.g. a cylindrical chamber having a diameter of about 2 inches in a lower portion and having a diameter of from about 4 to about 12 inches in an upper portion). Such dimensions are important to achieve the necessary conversion while at the same time affording criticality control and transportability of the cell and product. The reaction chamber further comprises an upper port and a lower port, the lower port allowing for the entry of reactant gases into the reaction chamber, the upper port allowing for the exit of gases from the reaction chamber. A diffuser plate is attached to the lower port of the reaction chamber and serves to shape the flow of gas into the reaction chamber. The reaction cell further comprises means for introducing gases into the reaction chamber and a heating means capable of heating the contents of the reaction chamber. The present invention also relates to a method for converting uranium metal to uranium oxide in the reaction cell of the present invention. The invention is useful for down-blending highly enriched uranium metal by the simultaneous conversion of highly enriched uranium metal and natural or depleted uranium metal to uranium oxide within the reaction cell. 4 figs.

  16. Compact reaction cell for homogenizing and down-blanding highly enriched uranium metal

    DOE Patents [OSTI]

    McLean, II, William (Oakland, CA); Miller, Philip E. (Livermore, CA); Horton, James A. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    The invention is a specialized reaction cell for converting uranium metal to uranium oxide. In a preferred form, the reaction cell comprises a reaction chamber with increasing diameter along its length (e.g. a cylindrical chamber having a diameter of about 2 inches in a lower portion and having a diameter of from about 4 to about 12 inches in an upper portion). Such dimensions are important to achieve the necessary conversion while at the same time affording criticality control and transportability of the cell and product. The reaction chamber further comprises an upper port and a lower port, the lower port allowing for the entry of reactant gasses into the reaction chamber, the upper port allowing for the exit of gasses from the reaction chamber. A diffuser plate is attached to the lower port of the reaction chamber and serves to shape the flow of gas into the reaction chamber. The reaction cell further comprises means for introducing gasses into the reaction chamber and a heating means capable of heating the contents of the reaction chamber. The present invention also relates to a method for converting uranium metal to uranium oxide in the reaction cell of the present invention. The invention is useful for down-blending highly enriched uranium metal by the simultaneous conversion of highly enriched uranium metal and natural or depleted uranium metal to uranium oxide within the reaction cell.

  17. The Birth of a Galaxy: Primoridal Metal Enrichment and Population II Stellar Populations

    E-Print Network [OSTI]

    Wise, John H; Norman, Michael L; Abel, Tom

    2010-01-01T23:59:59.000Z

    Population III stars first form in dark matter halos with masses around 10^6 Msun. By definition, they are metal-free, and their protostellar collapse is driven by molecular hydrogen cooling in the gas-phase, leading to a massive characteristic mass ~100 Msun and suppressed fragmentation. Population II stars with lower characteristic masses form when the star-forming gas reaches a critical metallicity of 10^{-6} - 10^{-3.5} Zsun, depending on whether dust cooling is important. We present adaptive mesh refinement radiation hydrodynamics simulations that follows the transition from Population III to II star formation. We model stellar radiative feedback with adaptive ray tracing. A top-heavy initial mass function for the Population III stars is considered, resulting in a plausible distribution of pair-instability supernovae and associated metal enrichment. We find that the gas fraction recovers from 5 percent to nearly the cosmic fraction in halos with merger histories rich in halos above 10^7 Msun. A single pa...

  18. Automated UF6 Cylinder Enrichment Assay: Status of the Hybrid Enrichment Verification Array (HEVA) Project: POTAS Phase II

    SciTech Connect (OSTI)

    Jordan, David V.; Orton, Christopher R.; Mace, Emily K.; McDonald, Benjamin S.; Kulisek, Jonathan A.; Smith, Leon E.

    2012-06-01T23:59:59.000Z

    Pacific Northwest National Laboratory (PNNL) intends to automate the UF6 cylinder nondestructive assay (NDA) verification currently performed by the International Atomic Energy Agency (IAEA) at enrichment plants. PNNL is proposing the installation of a portal monitor at a key measurement point to positively identify each cylinder, measure its mass and enrichment, store the data along with operator inputs in a secure database, and maintain continuity of knowledge on measured cylinders until inspector arrival. This report summarizes the status of the research and development of an enrichment assay methodology supporting the cylinder verification concept. The enrichment assay approach exploits a hybrid of two passively-detected ionizing-radiation signatures: the traditional enrichment meter signature (186-keV photon peak area) and a non-traditional signature, manifested in the high-energy (3 to 8 MeV) gamma-ray continuum, generated by neutron emission from UF6. PNNL has designed, fabricated, and field-tested several prototype assay sensor packages in an effort to demonstrate proof-of-principle for the hybrid assay approach, quantify the expected assay precision for various categories of cylinder contents, and assess the potential for unsupervised deployment of the technology in a portal-monitor form factor. We refer to recent sensor-package prototypes as the Hybrid Enrichment Verification Array (HEVA). The report provides an overview of the assay signatures and summarizes the results of several HEVA field measurement campaigns on populations of Type 30B UF6 cylinders containing low-enriched uranium (LEU), natural uranium (NU), and depleted uranium (DU). Approaches to performance optimization of the assay technique via radiation transport modeling are briefly described, as are spectroscopic and data-analysis algorithms.

  19. Recovery of enriched stable isotopes in radionuclide production

    SciTech Connect (OSTI)

    Razbash, A.A.; Sevastyanov, Yu.G.; Polyakov, O.N.; Krasnov, N.N.; Konyakhin, N.A.; Tolstouhov, Yu.V.; Maklachkov, A.G. [Cyclotron Co. Ltd., Obninsk (Russian Federation)

    1994-12-31T23:59:59.000Z

    The wide application of radionuclides in different fields of science and industry demanded an increase of their production. One of the ways to increase the radionuclide production on present cyclotrons is the use of the targets from enriched stable isotopes. This allows one to raise the productivity in some cases by two or more times and to increase radionuclidic purity. It should be noted, however, that enriched stable isotopes are very expensive. Therefore it is advisable to use such raw materials more than once. In the last ten years, The authors have used stable isotopes extensively for making of targets. Zinc-67 and zinc-68, cadmium-111 and cadmium-112, nickel-58, silver-109, thallium-203 have been employed for the production of gallium-67, indium-111, cobalt-57, cadmium-109 and thallium-201, respectively. The technique for the recovery of enriched stable isotopes has been developed. In this report the schemes of the recovering processes are presented.

  20. Electron spin decoherence in isotope-enriched silicon

    E-Print Network [OSTI]

    Wayne M. Witzel; Malcolm S. Carroll; Andrea Morello; Lukasz Cywinski; S. Das Sarma

    2010-10-27T23:59:59.000Z

    Silicon is promising for spin-based quantum computation because nuclear spins, a source of magnetic noise, may be eliminated through isotopic enrichment. Long spin decoherence times, $T_2$, have been measured in isotope-enriched silicon but come far short of the $T_2 = 2 T_1$ limit. The effect of nuclear spins on $T_2$ is well established. However, the effect of background electron spins from ever present residual phosphorus impurities in silicon can also produce significant decoherence. We study spin decoherence decay as a function of donor concentration, $^{29}$Si concentration, and temperature using cluster expansion techniques specifically adapted to the problem of a sparse dipolarly coupled electron spin bath. Our results agree with the existing experimental spin echo data in Si:P and establish the importance of background dopants as the ultimate decoherence mechanism in isotope-enriched silicon.

  1. Reduced enrichment for research and test reactors: Proceedings

    SciTech Connect (OSTI)

    Not Available

    1988-05-01T23:59:59.000Z

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

  2. Enrichment of the High-Redshift IGM by Galactic Winds

    E-Print Network [OSTI]

    A. Aguirre; J. Schaye; L. Hernquist; D. Weinberg; N. Katz; J. Gardner

    2001-09-17T23:59:59.000Z

    This paper discusses a semi-numerical method of investigating the enrichment of the intergalactic medium by galactic winds. We find that most galaxies at z >~ 3 should be driving winds, and that (if these winds are similar to those at low-z) these winds should escape to large distances. Our calculations -- which permit exploration of a large region of model parameter space -- indicate that the wind velocity, the mass of the wind-driving galaxies, the fraction of ambient material entrained, and the available time (between wind launch and the observed redshift) all affect wind propagation significantly; other physical effects can be important but are sub-dominant. We find that under reasonable assumptions, the enrichment by 3 enrichment is compatible with the intergalactic medium's detailed metal distribution or relative quiescence.

  3. Enrichment Zoning Options for the Small Nuclear Rocket Engine (SNRE)

    SciTech Connect (OSTI)

    Bruce G. Schnitzler; Stanley K. Borowski

    2010-07-01T23:59:59.000Z

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. In NASA’s recent Mars Design Reference Architecture (DRA) 5.0 study (NASA-SP-2009-566, July 2009), nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option because of its high thrust and high specific impulse (-900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art design incorporating lessons learned from the very successful technology development program. Past activities at the NASA Glenn Research Center have included development of highly detailed MCNP Monte Carlo transport models of the SNRE and other small engine designs. Preliminary core configurations typically employ fuel elements with fixed fuel composition and fissile material enrichment. Uniform fuel loadings result in undesirable radial power and temperature profiles in the engines. Engine performance can be improved by some combination of propellant flow control at the fuel element level and by varying the fuel composition. Enrichment zoning at the fuel element level with lower enrichments in the higher power elements at the core center and on the core periphery is particularly effective. Power flattening by enrichment zoning typically results in more uniform propellant exit temperatures and improved engine performance. For the SNRE, element enrichment zoning provided very flat radial power profiles with 551 of the 564 fuel elements within 1% of the average element power. Results for this and alternate enrichment zoning options for the SNRE are compared.

  4. Basic characterization of highly enriched uranium by gamma spectrometry

    E-Print Network [OSTI]

    Cong Tam Nguyen; Jozsef Zsigrai

    2005-08-25T23:59:59.000Z

    Gamma-spectrometric methods suitable for the characterization of highly enriched uranium samples encountered in illicit trafficking of nuclear materials are presented. In particular, procedures for determining the 234U, 235U, 238U, 232U and 236U contents and the age of highly enriched uranium are described. Consequently, the total uranium content and isotopic composition can be calculated. For determining the 238U and 232U contents a low background chamber was used. In addition, age dating of uranium was also performed using low-background spectrometry.

  5. Basic characterization of highly enriched uranium by gamma spectrometry

    E-Print Network [OSTI]

    Nguyen, C T

    2006-01-01T23:59:59.000Z

    Gamma-spectrometric methods suitable for the characterization of highly enriched uranium samples encountered in illicit trafficking of nuclear materials are presented. In particular, procedures for determining the 234U, 235U, 238U, 232U and 236U contents and the age of highly enriched uranium are described. Consequently, the total uranium content and isotopic composition can be calculated. For determining the 238U and 232U contents a low background chamber was used. In addition, age dating of uranium was also performed using low-background spectrometry.

  6. EIS-0240: Disposition of Surplus Highly Enriched Uranium

    Broader source: Energy.gov [DOE]

    The Department proposes to eliminate the proliferation threat of surplus highly enriched uranium (HEU) by blending it down to low enriched uranium (LEU), which is not weapons-usable. The EIS assesses the disposition of a nominal 200 metric tons of surplus HEU. The Preferred Alternative is, where practical, to blend the material for use as LEU and use overtime, in commercial nuclear reactor field to recover its economic value. Material that cannot be economically recovered would be blended to LEU for disposal as low-level radioactive waste.

  7. Enrichment of selected fatty acids in broiler tissues

    E-Print Network [OSTI]

    Yau, Jia-Chyi

    1990-01-01T23:59:59.000Z

    ENRICHMENT OF SELECTED FATTY ACIDS IN BROILER TISSUES A Thesis by JIA-CHYI YAU Submitted to the Office of Graduate Study of Texas A&M University in partial fullfillment of the requirements for the degree of MASTER OF SCIENCE August 1990... Major Subject: Food Science and Technology ENRICHMENT OF SELECTED FATTY ACIDS IN BROILER TISSUES A Thesis by JIA-CHYI YAU Approved as to style and content by A. R. Sams (Chair of Comittee) C. A. Bailey (Member) J. T Eeet n (M mber) R. Creg...

  8. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 7, NO. 5, SEPTEMBER 1999 567 Centrifugal Compressor Surge and Speed Control

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Compressor Surge and Speed Control Jan Tommy Gravdahl, Member, IEEE, and Olav Egeland, Member, IEEE Abstract--Previous work on stabilization of compressor surge is extended to include control of the angular velocity of the compressor. First a low-order centrifugal compressor model is presented where the states are mass flow

  9. The performance of a multiple-disk centrifugal pump as an artificial ventricle over a wide range of operating parameters

    E-Print Network [OSTI]

    Sidhu, Amrita Singh

    1993-01-01T23:59:59.000Z

    The performance of a multiple-disk centrifugal pump based on the Tesla Turbine design is tested over a wide range of operating conditions. 'This pump is tested on a mock circulatory loop (with a blood analog) approved by the NIH. This valveless...

  10. INSIGHTS INTO PRE-ENRICHMENT OF STAR CLUSTERS AND SELF-ENRICHMENT OF DWARF GALAXIES FROM THEIR INTRINSIC METALLICITY DISPERSIONS

    SciTech Connect (OSTI)

    Leaman, Ryan, E-mail: rleaman@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 1A1 (Canada)

    2012-12-01T23:59:59.000Z

    Star clusters are known to have smaller intrinsic metallicity spreads than dwarf galaxies due to their shorter star formation timescales. Here we use individual spectroscopic [Fe/H] measurements of stars in 19 Local Group dwarf galaxies, 13 Galactic open clusters, and 49 globular clusters to show that star cluster and dwarf galaxy linear metallicity distributions are binomial in form, with all objects showing strong correlations between their mean linear metallicity Z-bar and intrinsic spread in metallicity {sigma}(Z){sup 2}. A plot of {sigma}(Z){sup 2} versus Z-bar shows that the correlated relationships are offset for the dwarf galaxies from the star clusters. The common binomial nature of these linear metallicity distributions can be explained with a simple inhomogeneous chemical evolution model, where the star cluster and dwarf galaxy behavior in the {sigma}(Z){sup 2}- Z-bar diagram is reproduced in terms of the number of enrichment events, covering fraction, and intrinsic size of the enriched regions. The inhomogeneity of the self-enrichment sets the slope for the observed dwarf galaxy {sigma}(Z){sup 2}- Z-bar correlation. The offset of the star cluster sequence from that of the dwarf galaxies is due to pre-enrichment, and the slope of the star cluster sequence represents the remnant signature of the self-enriched history of their host galaxies. The offset can be used to separate star clusters from dwarf galaxies without a priori knowledge of their luminosity or dynamical mass. The application of the inhomogeneous model to the {sigma}(Z){sup 2}- Z-bar relationship provides a numerical formalism to connect the self-enrichment and pre-enrichment between star clusters and dwarf galaxies using physically motivated chemical enrichment parameters. Therefore we suggest that the {sigma}(Z){sup 2}- Z-bar relationship can provide insight into what drives the efficiency of star formation and chemical evolution in galaxies, and is an important prediction for galaxy simulation models to reproduce.

  11. Quantum states of neutrons in the gravitational and centrifugal potentials in a new GRANIT spectrometer

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    We will discuss the scientific program to be studied in a new gravitational spectrometer GRANIT in a broad context of quantum states (quantum behaviour) of ultracold neutrons (UCN) in gravitational [1] and centrifugal [2] potentials, as well as applications of these phenomena/spectrometer to various domains of physics, ranging from studies of fundamental short-range interactions and symmetries to neutron quantum optics and reflectometry using UCN. All these topics, as well as related instrumental and methodical developments have been discussed during dedicated GRANIT-2010 Workshop [3]. The GRANIT spectrometer has been recently installed at the Institut Laue-Langevin, Grenoble, France [4] and could become operational in near future. 1. V.V. Nesvizhevsky et al (2002), Nature 415, 297. 2. V.V. Nesvizhevsky et al (2010), Nature Physics 6, 114. 3. GRANIT-2010, Les Houches, 14-19 february 2010. 4. M. Kreuz et al (2009), NIM 611, 326.

  12. OPTIMIZING CENTRIFUGAL BARREL POLISHING FOR MIRROR FINISH SRF CAVITY AND RF TESTS AT JEFFERSON LAB

    SciTech Connect (OSTI)

    Ari Palczewski, Rongli Geng, Hui Tian

    2012-07-01T23:59:59.000Z

    We performed Centrifugal Barrel Polishing (CBP) on a 1.3 GHz fine grain TESLA single cell cavity and 1.5 GHz fine grain CEBAF high gradient superconducting radio frequency (SRF) single cell cavity following a modified recipe originally developed at Fermi National Accelerator Lab (FNAL). We were able to obtain a mirror like surface similar to that obtained at FNAL, while reducing the number of CBP steps and total processing time. This paper will discuss the change in surface and subsequent cavity performance post CBP, after a 800 C bake (no pre-bake chemistry) and minimal controlled electro-polishing (10 micron). In addition to Q vs. E{sub ACC} thermometry mapping with preheating characteristics and optical inspection of the cavity after CBP will also be shown.

  13. Comparison of soft computing techniques for a three-phase oil field centrifuge.

    SciTech Connect (OSTI)

    Smith, R. E. (Ronald E.); Parkinson, w; Miller, N. (Neal)

    2002-01-01T23:59:59.000Z

    In this work we compare fuzzy techniques to neural network techniques for building a soft sensor for a three-phase oil field centrifuge. The soft sensor is used in a feed-forward control system that augments a feedback control system. Two approaches were used to develop the soft sensor. The first approach was to use a fuzzy rule based system based upon the experience of an expert operator. The expert operator's experience was supplemented using a computer model of the system. The second approach was to use a neural network to build the inverse of the computer model. The pros and cons of both techniques are discussed. KEYWORDS: fuzzy logic, neural networks, soft sensor, soft computing

  14. Discovery of a Centrifugal Magnetosphere Around the He-Strong Magnetic B1 Star ALS 3694

    E-Print Network [OSTI]

    Shultz, Matt; Rivinius, Thomas; Sikora, James

    2014-01-01T23:59:59.000Z

    We report the results of 6 nights of Canada-France-Hawaii Telescope spectropolarimetric ESPaDOnS observations of the He-strong, magnetic B1 type star ALS 3694. The longitudinal magnetic field is approximately 2 kG in all 6 observations, showing essentially no variation between nights. The H$\\alpha$ line displays variable emission on all nights, peaking at high velocities ($\\sim 3 v\\sin{i}$). Given the presence of a strong ($B_{\\rm d}>$6 kG) magnetic field, and the similarity of the emission profile to that of other magnetic B-type stars, we interpret the emission as a consequence of a centrifugal magnetosphere.

  15. An improved approximation scheme for the centrifugal term and the Hulthen potential

    E-Print Network [OSTI]

    Sameer M. Ikhdair

    2009-01-07T23:59:59.000Z

    We present a new approximation scheme for the centrifugal term to solve the Schrodinger equation with the Hulthen potential for any arbitrary l state by means of a mathematical Nikiforov-Uvarov (NU) method. We obtain the bound state energy eigenvalues and the normalized corresponding eigenfunctions expressed in terms of the Jacobi polynomials or hypergeometric functions for a particle exposed to this potential field. Our numerical results of the energy eigenvalues are found to be in high agreement with those results obtained by using the program based on a numerical integration procedure. The s-wave (l=0) analytic solution for the binding energies and eigenfunctions of a particle are also calculated. The physical meaning of the approximate analytical solution is discussed. The present approximation scheme is systematic and accurate.

  16. Centrifugal instability of Stokes layers in crossflow: the case of a forced cylinder wake

    E-Print Network [OSTI]

    D'Adamo, Juan; Wesfreid, José Eduardo

    2015-01-01T23:59:59.000Z

    The wake flow around a circular cylinder at $Re\\approx100$ performing rotatory oscillations has been thoroughly discussed in the literature, mostly focusing on the modifications to the natural B\\'enard-von K\\'arm\\'an vortex street that result from the forced shedding modes locked to the rotatory oscillation frequency. The usual experimental and theoretical frameworks at these Reynolds numbers are quasi-two-dimensional, since the secondary instabilities bringing a three-dimensional structure to the cylinder wake flow occur only at higher Reynolds numbers. In the present paper we show that a three-dimensional structure can appear below the usual three-dimensionalization threshold, when forcing with frequencies lower than the natural vortex shedding frequency, at high amplitudes, as a result of a previously unreported mechanism: a pulsed centrifugal instability of the oscillating Stokes layer at the wall of the cylinder. The present numerical investigation lets us in this way propose a physical explanation for t...

  17. Experimental and simulation studies of water-alternating-enriched gas injection for San Francisco Field, Colombia

    E-Print Network [OSTI]

    Soto Tavera, Claudia Patricia

    2003-01-01T23:59:59.000Z

    :82. 27cm)(pore xoiumeh ~ Solvent &nl ection rate: 0. 1 (375 cm "min. ~ Slim-tuh? temperature: 120"F. ~ Back-pressure regulator temperature: 120" F. ~ Siii?-tub? prcssure: 1, 050 psia. ~ l3a?l'-pressiir? r?gu). itor pr?ssure: 1. 050 psia. 10...

  18. Reduced enrichment for research and test reactors: Proceedings

    SciTech Connect (OSTI)

    Not Available

    1993-07-01T23:59:59.000Z

    The 15th annual Reduced Enrichment for Research and Test Reactors (RERTR) international meeting was organized by Ris{o} National Laboratory in cooperation with the International Atomic Energy Agency and Argonne National Laboratory. The topics of the meeting were the following: National Programs, Fuel Fabrication, Licensing Aspects, States of Conversion, Fuel Testing, and Fuel Cycle. Individual papers have been cataloged separately.

  19. Genetic engineering of syringyl-enriched lignin in plants

    DOE Patents [OSTI]

    Chiang, Vincent Lee; Li, Laigeng

    2004-11-02T23:59:59.000Z

    The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.

  20. Enrichment Assay Methods Development for the Integrated Cylinder Verification System

    SciTech Connect (OSTI)

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

    2009-10-22T23:59:59.000Z

    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.

  1. The IMCA: A field instrument for uranium enrichment measurements

    SciTech Connect (OSTI)

    Gardner, G.H.; Koskelo, M.; Moeslinger, M. [Canberra Industries, Meriden, CT (United States); Mayer, R.L. II; McGinnis, B.R. [Lockheed Martin Utility Services, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant; Wishard, B. [International Atomic Energy Agency, Vienna (Austria)

    1996-12-31T23:59:59.000Z

    The IMCA (Inspection Multi-Channel Analyzer) is a portable gamma-ray spectrometer designed to measure the enrichment of uranium either in a laboratory or in the field. The IMCA consists of a Canberra InSpector Multi-Channel Analyzer, sodium iodide or a planar germanium detector, and special application software. The system possesses a high degree of automation. The IMCA uses the uranium enrichment meter principle, and is designed to meet the International Atomic Energy Agency (IAEA) requirements for the verification of enriched uranium materials. The IMCA is available with MGA plutonium isotopic analysis software or MGAU uranium analysis software as well. In this paper, the authors present a detailed description of the hardware and software of the IMCA system, as well as results from preliminary measurements testing compliance of IMCA with IAEA requirements using uranium standards and UF6 cylinders. Measurements performed on UF6 cylinders in the field under variable environmental conditions (temperatures ranging from 0 to 35 C) have shown that good results can be achieved. The enrichment of UF6 contained in the cylinder is determined by using calibration constants generated from an instrument calibration, using traceable uranium oxide standards, performed in the laboratory under controlled environmental conditions. The IMCA software is designed to make the necessary matrix and container corrections to ensure that accurate results are achieved in the field.

  2. CO2 enrichment increases carbon and nitrogen input from

    E-Print Network [OSTI]

    CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest Colleen2 Ecological Society of America, 2008 #12;#12;#12;#12;#12;+ [CO2] #12;+ Net primary production + [CO2] #12;+ Net primary production + [CO2] + C and N storage in biomass #12;+ Net primary production

  3. CRAD, Training- Y-12 Enriched Uranium Operations Oxide Conversion Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a January 2005 assessment of the Training Program at the Y-12 - Enriched Uranium Operations Oxide Conversion Facility.

  4. UniSAConnect Enriching education opportunities for secondary schools

    E-Print Network [OSTI]

    Mayer, Wolfgang

    to develop a sustainable solution to water access problems in remote communities. The Engineers WithoutUniSAConnect Enriching education opportunities for secondary schools and the community. #12;2 Uni program engages with secondary schools and the community to inspire further study and educational

  5. Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive

    E-Print Network [OSTI]

    Williamson, Craig E.

    Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen J A S M I N E E . S A R received May 26, 2010. Accepted May 28, 2010. Alpine glaciers have receded substantially over the last. Our results demonstrate that the presence of glaciers on alpine watersheds more strongly influences NO

  6. Polymer Simulations with Pruned-Enriched Rosenbluth Method

    E-Print Network [OSTI]

    Hsu, Hsiao-Ping

    Polymer Simulations with Pruned-Enriched Rosenbluth Method I Hsiao-Ping Hsu Institut f¨ur Physik, Johannes Gutenberg-Universit¨at Mainz, Germany Polymer simulations with PERM I ­ p. #12;Introduction Polymer: a long molecule consisting of many similar or identical monomers linked together Polyethylene

  7. CenterPoint The Center for Academic Enrichment & Outreach Newsletter

    E-Print Network [OSTI]

    Hemmers, Oliver

    CenterPoint July 2010 The Center for Academic Enrichment & Outreach Newsletter ONLINE ARTICLES Students' Encountered While in Washington D.C. By Dr. Emmanuel Ayim, Upward Bound Academic Counselor #12 disadvantaged backgrounds and have demonstrated strong academic potential. Program staff members work closely

  8. Reduced-Enrichment Research and Test Reactor Program: Environmental assessment

    SciTech Connect (OSTI)

    Not Available

    1980-05-01T23:59:59.000Z

    The principal program objective and principal part of the proposed action is to improve the proliferation resistance of nuclear fuels used in research and test reactors by providing the technical means (through technical development, design, and testing) for reducing the uranium enrichment requirements of these fuels to substantially less than the 90 to 93% enrichment currently used. Operator acceptance of the reduced-enrichment-uranium (REU) fuel alternative will require minimizing of reactor performance reduction, fuel cycle cost increases, the number of new safety and licensing issues raised, and reactor and facility modifications. The other part of the proposed action is to assure the capability for commercial production and supply of REU fuel for use both in the US and abroad. The RERTR Program scope is limited to generic design studies, technical support to reactor operating organizations in preparing for conversions to REU fuels, fuel development, fuel demonstrations, and technical support for commercialization of REU fuels. This environmental assessment addresses the environmental consequences of RERTR Program activities and of specific conversions of typical reactors (the Ford Nuclear Reactor and one or two other to-be-designated demonstrations) to REU-fuel cycles, including domestic and international shipments of enriched uranium pertinent to the conduct of RERTR Program activities.

  9. CRAD, Management- Y-12 Enriched Uranium Operations Oxide Conversion Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a January 2005 assessment of Management program at the Y-12 - Enriched Uranium Operations Oxide Conversion Facility.

  10. Microchip method for the enrichment of specific DNA sequences

    DOE Patents [OSTI]

    Mirzabekov, A.D.; Lysov, Y.P.; Shick, V.V.; Dubiley, S.A.

    1998-12-22T23:59:59.000Z

    A method for enriching specific genetic material sequences is provided, whereby oligonucleotide molecules complementary to the desired genetic material is first used to isolate the genetic material from a first source of genomic material. Then the genetic material is used as a label to isolate similar genetic sequences from other sources. 4 figs.

  11. Microchip method for the enrichment of specific DNA sequences

    DOE Patents [OSTI]

    Mirzabekov, Andrei Darievich (Moscow, RU); Lysov, Yuri Petrovich (Moscow, RU); Shick, Valentine Vladimirovich (Hinsdale, IL); Dubiley, Svetlana Alekseevna (Moscow, RU)

    1998-01-01T23:59:59.000Z

    A method for enriching specific genetic material sequences is provided, whereby oligonucleotide molecules complementary to the desired genetic material is first used to isolate the genetic material from a first source of genomic material. Then the genetic material is used as a label to isolate similar genetic sequences from other sources.

  12. New extruder-based deuterium feed system for centrifuge pellet injection

    SciTech Connect (OSTI)

    Combs, S.K.; Foust, C.R. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071 (United States)

    1997-12-01T23:59:59.000Z

    The pellet injection systems for the next-generation fusion devices (such as the International Thermonuclear Experimental Reactor) and future fusion reactors will have to provide deuterium-tritium fueling for much longer pulse lengths (up to {approx}1000s) than present applications (typically limited to less than several seconds). Thus, a prototype pellet feed system for centrifuge pellet injection has been developed and used in long-pulse ({gt}100s) tests at the Oak Ridge National Laboratory (ORNL). The new apparatus has two key components: (1) a cryogenic deuterium extruder and (2) an electromagnetic pellet punch mechanism. For maximum testing flexibility, the prototype is equipped with several other active components that allow remote adjustments, including precise positioning of the punch and the capability to index through eight different pellet lengths. The new feed system was designed to mate with an existing centrifuge accelerator facility at ORNL, and experiments in the facility were carried out to document the performance and reliability of the new feed system. With 2.3-mm-diam deuterium pellets and a catenary-shaped accelerator ({approx}1.2mdiam), the prototype feed system was found to be capable of placing up to {approx}90{percent} of the punched pellets in the proper time/space window for pickup and acceleration by the high-speed rotating ({approx}50Hz) arbor. For these operating parameters, the pellet nominal speed was {approx}430m/s, and maximum pellet feed rates of 10 pellets/s and greater were tested. In this article the equipment is briefly described, and the experimental test results are summarized. Also, issues affecting overall pellet delivery efficiency are discussed. {copyright} {ital 1997 American Institute of Physics.}

  13. The influence of quantum field fluctuations on chaotic dynamics of Yang-Mills system II. The role of the centrifugal term

    E-Print Network [OSTI]

    V. I. Kuvshinov; A. V. Kuzmin; V. A. Piatrou

    2005-11-27T23:59:59.000Z

    We have considered SU(2)xU(1) gauge field theory describing electroweak interactions. We have demonstrated that centrifugal term in model Hamiltonian increases the region of regular dynamics of Yang-Mills and Higgs fields system at low densities of energy. Also we have found analytically the approximate relation for critical density of energy of the order to chaos transition on centrifugal constant. It is necessary to note that mentioned increase of the region of regular dynamics has linear dependance on the value of the centrifugal constant.

  14. Gas sensor

    DOE Patents [OSTI]

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09T23:59:59.000Z

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  15. Development of a low enrichment uranium core for the MIT reactor

    E-Print Network [OSTI]

    Newton, Thomas Henderson

    2006-01-01T23:59:59.000Z

    An investigation has been made into converting the MIT research reactor from using high enrichment uranium (HEU) to low enrichment uranium (LEU) with a newly developed fuel material. The LEU fuel introduces negative ...

  16. A finite element method and the method of finite spheres enriched for analysis of wave propagations

    E-Print Network [OSTI]

    Ham, Seounghyun, 1982-

    2014-01-01T23:59:59.000Z

    The objective of this thesis is to present a finite element method and the method of finite spheres enriched for the solution of various wave propagation problems. The first part of this thesis is to present an enriched ...

  17. Comparison of enrichment techniques for the isolation of Salmonella sp. from swine feces

    E-Print Network [OSTI]

    Andrews, Kimberley Denise

    2001-01-01T23:59:59.000Z

    seven comparative techniques for isolation. A standard protocol, consisting of xylose lysine tergitol-4 agar (XLT4) paired with a primary enrichment in tetrathionate broth with iodine (TTH) and secondary enrichment in Rappaport-Vassiliadis R10 broth (RV...

  18. o Take courses for personal enrichment ONLY. o Other, please explain

    E-Print Network [OSTI]

    Rose, Michael R.

    o Take courses for personal enrichment ONLY. o Other, please explain: ACADEMIC PLANNING FORM courses related to my major for my personal enrichment. List below the TITLES of courses in which you wish

  19. NATURAL GAS MARKET ASSESSMENT

    E-Print Network [OSTI]

    CALIFORNIA ENERGY COMMISSION NATURAL GAS MARKET ASSESSMENT PRELIMINARY RESULTS In Support.................................................................................... 6 Chapter 2: Natural Gas Demand.................................................................................................. 10 Chapter 3: Natural Gas Supply

  20. Natural uranium/conversion services/enrichment services

    SciTech Connect (OSTI)

    NONE

    1993-12-31T23:59:59.000Z

    This article is the 1993 uranium market summary. During this reporting period, there were 50 deals in the concentrates market, 26 deals in the UF6 market, and 14 deals for enrichment services. In the concentrates market, the restricted value closed $0.15 higher at $9.85, and the unrestricted value closed down $0.65 at $7.00. In the UF6 market, restricted prices fluctuated and closed higher at $31.00, and unrestricted prices closed at their initial value of $24.75. The restricted transaction value closed at $10.25 and the unrestricted value closed at $7.15. In the enrichment services market, the restricted value moved steadily higher to close at $84.00 per SWU, and the unrestricted value closed at its initial value of $68.00 per SWU.