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Uncompensated magnetization and exchange-bias field in La0.7Sr0.3MnO3/YMnO3 bilayers: The influence of the ferromagnetic layer (open access)

Uncompensated magnetization and exchange-bias field in La0.7Sr0.3MnO3/YMnO3 bilayers: The influence of the ferromagnetic layer

None
Date: May 23, 2011
Creator: Zandalazini, C.; Esquinazi, P.; Bridoux, G.; Barzola-Quiquia, J.; Ohldag, H. & Arenholz, E.
Object Type: Article
System: The UNT Digital Library
Comment on Li pellet Conditioning in TFTR (open access)

Comment on Li pellet Conditioning in TFTR

Li pellet conditioning in TFTR results in a reduction of the edge electron density which allows increased neutral beam penetration, central heating, and fueling. Consequently the temperature profiles became more peaked with higher central Ti, Te, and neutron emission rates.
Date: May 23, 2011
Creator: Budny, R.V.
Object Type: Report
System: The UNT Digital Library
Laboratory Evaluation of LED T8 Replacement Lamp Products (open access)

Laboratory Evaluation of LED T8 Replacement Lamp Products

A report on a lab setting analysis involving LED lamps intended to directly replace T8 fluorescent lamps (4') showing light output, power, and economic comparisons with other fluorescent options.
Date: May 23, 2011
Creator: Richman, Eric E.; Kinzey, Bruce R. & Miller, Naomi J.
Object Type: Report
System: The UNT Digital Library
Hidden magnetic configuration in epitaxial La1-rSrzMnO3 films (open access)

Hidden magnetic configuration in epitaxial La1-rSrzMnO3 films

We present an unreported magnetic configuration in epitaxial La{sub 1-x}Sr{sub x}MnO{sub 3} (x {approx} 0.3) (LSMO) films grown on strontium titanate (STO). X-ray magnetic circular dichroism indicates that the remanent magnetic state of thick LSMO films is opposite to the direction of applied magnetic field. Spectroscopic and scattering measurements reveal that the average Mn valence varies from mixed Mn{sup 3+}/Mn{sup 4+} to an enriched Mn{sup 3+} region near the STO interface, resulting in a compressive lattice along a, b-axis and a possible electronic reconstruction in the Mn e{sub g} orbital (d{sub 3z{sup 2}-r{sup 2}}). This reconstruction may provide a mechanism for coupling the Mn{sup 3+} moments antiferromagnetically along the surface normal direction, and in turn may lead to the observed reversed magnetic configuration.
Date: May 23, 2011
Creator: Kao, Chi-Chang
Object Type: Article
System: The UNT Digital Library
OECD MMCI 2-D Core Concrete Interaction (CCI) Tests : CCCI-1 Test Data Report-Thermalhydraulic Results. Rev 0 January 31, 2004. (open access)

OECD MMCI 2-D Core Concrete Interaction (CCI) Tests : CCCI-1 Test Data Report-Thermalhydraulic Results. Rev 0 January 31, 2004.

The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten coreconcrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed …
Date: May 23, 2011
Creator: Farmer, M. T.; Lomperski, S.; Aeschlimann, R. W. & Basu, S. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry. (open access)

Computational fluid dynamics analyses of lateral heat conduction, coolant azimuthal mixing and heat transfer predictions in a BR2 fuel assembly geometry.

To support the analyses related to the conversion of the BR2 core from highly-enriched (HEU) to low-enriched (LEU) fuel, the thermal-hydraulics codes PLTEMP and RELAP-3D are used to evaluate the safety margins during steady-state operation (PLTEMP), as well as after a loss-of-flow, loss-of-pressure, or a loss of coolant event (RELAP). In the 1-D PLTEMP and RELAP simulations, conduction in the azimuthal and axial directions is not accounted. The very good thermal conductivity of the cladding and the fuel meat and significant temperature gradients in the lateral directions (axial and azimuthal directions) could lead to a heat flux distribution that is significantly different than the power distribution. To evaluate the significance of the lateral heat conduction, 3-D computational fluid dynamics (CFD) simulations, using the CFD code STAR-CD, were performed. Safety margin calculations are typically performed for a hot stripe, i.e., an azimuthal region of the fuel plates/coolant channel containing the power peak. In a RELAP model, for example, a channel between two plates could be divided into a number of RELAP channels (stripes) in the azimuthal direction. In a PLTEMP model, the effect of azimuthal power peaking could be taken into account by using engineering factors. However, if the thermal mixing …
Date: May 23, 2011
Creator: Tzanos, C. P. & Dionne, B. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Beam break-up estimates for the ERL at BNL (open access)

Beam break-up estimates for the ERL at BNL

A prototype Ampere-class superconducting energy recovery linac (ERL) is under advanced construction at BNL. The ERL facility is comprised of a five-cell SC Linac plus a half-cell SC photo-injector RF electron gun, both operating at 703.75 MHz. The facility is designed for either a high-current mode of operation up to 0.5 A at 703.75 MHz or a high-bunch-charge mode of 5 nC at 10 MHz bunch frequency. The R&D facility serves a test bed for an envisioned electron-hadron collider, eRHIC. The high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory, and requires the determination of HOM tolerances for a cavity upgrade. The niobium cavity has been tested at superconducting temperatures and has provided measured quality factors (Q) for a large number of modes. These numbers were used for the estimate of the beam breakup instability (BBU). The facility will be assembled with a highly flexible lattice covering a vast operational parameter space for verification of the estimates and to serve as a test bed for the concepts directed at future projects.
Date: May 23, 2010
Creator: Ben-Zvi, Ilan; Calaga, R.; Hahn, H.; Hammons, L.; Johnson, E.; Kayran, D. et al.
Object Type: Article
System: The UNT Digital Library
Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux. (open access)

Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux.

This memo describes the assumptions and references used in determining the thermal properties for the various materials used in the BR2 HEU (93% enriched in {sup 235}U) to LEU (19.75% enriched in {sup 235}U) conversion feasibility analysis. More specifically, this memo focuses on the materials contained within the pressure vessel (PV), i.e., the materials that are most relevant to the study of impact of the change of fuel from HEU to LEU. This section is regrouping all of the thermal property tables. Section 2 provides a summary of the thermal properties in form of tables while the following sections present the justification of these values. Section 3 presents a brief background on the approach used to evaluate the thermal properties of the dispersion fuel meat and specific heat capacity. Sections 4 to 7 discuss the material properties for the following materials: (i) aluminum, (ii) dispersion fuel meat (UAlx-Al and U-7Mo-Al), (iii) beryllium, and (iv) stainless steel. Section 8 discusses the impact of irradiation on material properties. Section 9 summarizes the material properties for typical operating temperatures. Appendix A elaborates on how to calculate dispersed phase's volume fraction. Appendix B shows the evolution of the BR2 maximum heat flux with burnup.
Date: May 23, 2011
Creator: Dionne, B.; Kim, Y. S. & Hofman, G. L. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Scenarios For The ATF2 Ultra-Low Betas Proposal (open access)

Scenarios For The ATF2 Ultra-Low Betas Proposal

The current ATF2 Ultra-Low beta proposal was designed to achieve 20nm vertical IP beam size without considering the multipolar components of the FD magnets. In this paper we describe different scenarios that avoid the detrimental effect of these multipolar errors to the beam size at the interaction point (IP). The simplest approach consists in modifying the optics, but other solutions are studied as the introduction of super-conducting wigglers to reduce the emittance or the replacement of the normal-conducting focusing quadrupole in the Final Doublet (NC-QF1FF) with a super-conducting quadrupole one (SC-QF1FF). These are fully addressed in the paper.
Date: May 23, 2010
Creator: E., Marin; B., Parker & M., Tomas R. Bambade Kuroda S. Okugi T. Tauchi T. Terunuma N. Urakawa J. Seryi A. White G. Woodley
Object Type: Article
System: The UNT Digital Library
Environmental assessment for the Consumer Products Efficiency Standards program (open access)

Environmental assessment for the Consumer Products Efficiency Standards program

The Energy Policy and Conservation Act of 1975 as amended by the National Energy Conservation Policy Act of 1978, requires the DOE to prescribe energy efficiency standards for thirteen consumer products. The Consumer Products Efficiency Standards (CPES) program covers the following products: refrigerators and refrigerator-freezers; freezers;clothes dryers;water heaters; room air conditioners; home heating equipment (not including furnaces); kitchen ranges and ovens; central air conditioners (cooling and heat pumps); furnaces; dishwashers; television sets; clothes washers; and humidifiers and dehumidifiers. DOE is proposing two sets of standards for all thirteen consumer products: intermediate standards to become effective in 1981 for the first nine products and in 1982 for the second four products, and final standards to become effective in 1986 and 1987, respectively. The final standards are more restrictive than the intermediate standards and will provide manufacturers with the maximum time permitted under the Act to plan and develop extensive new lines of efficient consumer products. The final standards proposed by DOE require the maximum improvements in efficiency which are technologically feasible and economically justified, as required by Section 325(c) of EPCA. The thirteen consumer products account for approximately 90% of all the energy consumed in the nation's residences, or more than …
Date: May 23, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
OECD MMCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 test data report : thermal hydraulic results, Rev. 0 September 20, 2002. (open access)

OECD MMCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 test data report : thermal hydraulic results, Rev. 0 September 20, 2002.

The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench …
Date: May 23, 2011
Creator: Lomperski, S.; Farmer, M. T.; Kilsdonk, D. J.; Aeschlimann, R. W. & Basu, S.
Object Type: Report
System: The UNT Digital Library
Linear optics measurements and corrections using an AC dipole in RHIC (open access)

Linear optics measurements and corrections using an AC dipole in RHIC

We report recent experimental results on linear optics measurements and corrections using ac dipole. In RHIC 2009 run, the concept of the SVD correction algorithm is tested at injection energy for both identifying the artificial gradient errors and correcting it using the trim quadrupoles. The measured phase beatings were reduced by 30% and 40% respectively for two dedicated experiments. In RHIC 2010 run, ac dipole is used to measure {beta}* and chromatic {beta} function. For the 0.65m {beta}* lattice, we observed a factor of 3 discrepancy between model and measured chromatic {beta} function in the yellow ring.
Date: May 23, 2010
Creator: Wang, G.; Bai, M. & Yang, L.
Object Type: Article
System: The UNT Digital Library
A Model for Tow Impregnation and Consolidation for Partially Impregnated Thermoset Prepregs (open access)

A Model for Tow Impregnation and Consolidation for Partially Impregnated Thermoset Prepregs

The formation and transport of voids in composite materials remains a key research area in composite manufacturing science. Knowledge of how voids, resin, and fiber reinforcement propagate throughout a composite material continuum from green state to cured state during an automated tape layup process is key to minimizing defects induced by void-initiated stress concentrations under applied loads for a wide variety of composite applications. This paper focuses on modeling resin flow in a deforming fiber tow during an automated process of partially impregnated thermoset prepreg composite material tapes. In this work, a tow unit cell based model has been presented that determines the consolidation and impregnation of a thermoset prepreg tape under an input pressure profile. A parametric study has been performed to characterize the behavior of varying tow speed and compaction forces on the degree of consolidation. Results indicate that increased tow consolidation is achieved with slower tow speeds and higher compaction forces although the relationship is not linear. The overall modeling of this project is motivated to address optimization of the 'green state' composite properties and processing parameters to reduce or eliminate 'cured state' defects, such as porosity and de-lamination. This work is partially funded by the Department …
Date: May 23, 2011
Creator: Jr, John J. Gangloff; Sinha, Shatil & Advani, Suresh G.
Object Type: Article
System: The UNT Digital Library
Progress on Analytical Modeling of Coherent Electron Cooling (open access)

Progress on Analytical Modeling of Coherent Electron Cooling

We report recent progresses on analytical studies of Coherent Electron Cooling. The phase space electron beam distribution obtained from the 1D FEL amplifier is applied to an infinite electron plasma model and the electron density evolution inside the kicker is derived. We also investigate the velocity modulation in the modulator and obtain a closed form solution for the current density evolution for infinite homogeneous electron plasma.
Date: May 23, 2010
Creator: Wang, G.; Blaskiewicz, M.; Litvinenko, V. & Webb, S.
Object Type: Article
System: The UNT Digital Library
ASSEMBLY AND TEST OF A 120 MM BORE 15 T NB3SN QUADRUPOLE FOR THE LHC UPGRADE (open access)

ASSEMBLY AND TEST OF A 120 MM BORE 15 T NB3SN QUADRUPOLE FOR THE LHC UPGRADE

In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is to provide appropriate mechanical support to the coils. Compared to the previous LARP Technology Quadrupole and Long Quadrupole magnets, the purpose of HQ is also to demonstrate accelerator quality features such as alignment and cooling. So far, 8 HQ coils have been fabricated and 4 of them have been assembled and tested in HQ01a. This paper presents the mechanical assembly and test results of HQ01a.
Date: May 23, 2010
Creator: Felice, H.; Caspi, S.; Cheng, D.; Dietderich, D.; Ferracin, P.; Hafalia, R. et al.
Object Type: Article
System: The UNT Digital Library
Redox neptunium measurements (open access)

Redox neptunium measurements

Dissolver solution samples were analyzed for neptunium, and the data are plotted as g Np/t U vs g Pu/t U.
Date: May 23, 1963
Creator: Malody, C. W.
Object Type: Report
System: The UNT Digital Library
Tank characterization report for single-shell tank 241-C-109 (open access)

Tank characterization report for single-shell tank 241-C-109

One of the major functions of the Tank Waste Remediation System (TWRS) is to characterize wastes in support of waste management and disposal activities at the Hanford Site. Analytical data from sampling and analysis, along with other available information about a tank, are compiled and maintained in a tank characterization report (TCR). This report and its appendices serve as the TCR for single-shell tank 241-C-109. The objectives of this report are: (1) to use characterization data in response to technical issues associated with tank 241 C-109 waste; and (2) to provide a standard characterization of this waste in terms of a best-basis inventory estimate. The response to technical issues is summarized in Section 2.0, and the best-basis inventory estimate is presented in Section 3.0. Recommendations regarding safety status and additional sampling needs are provided in Section 4.0. Supporting data and information are contained in the appendices.
Date: May 23, 1997
Creator: Simpson, B. C.
Object Type: Report
System: The UNT Digital Library
Magnetometer calibration and test procedure (open access)

Magnetometer calibration and test procedure

Nuclear waste has been sluiced and pumped from storage tank 241-AX-104, leaving a contaminated heel volume. These operations did not include measurements of the removed waste volume leaving an unknown heel volume in the tank. A magnetometer transducer will be lowered through tank riser ports to rest on the heel`s surface. The heel thickness will control the distance between the transducer and the tank`s bottom The instrument`s output varies with the distance from a magnetic mass, such as the tank`s steel bottom, thereby enabling a measurement of the heel depth. Measurements at several tank locations will permit an estimate of the tank`s heel volume. The magnetometer`s output is influenced by adjacent magnetic materials, such as the tank walls, air lift circulators or other equipment installed in the tank. An adjacent vertical steel surface produces a voltage offset in the instrument`s output. Measurements near a tank wall or other tank components may be corrected by noting the offset before the instrument`s output is influenced by the tank bottom. An unlevel or uneven heel surface could orient the magnetometer transducer so that it is not vertically level. The magnetometer readings are influenced by these skewed transducer orientations. The magnitude of these errors …
Date: May 23, 1997
Creator: Squier, D. M.
Object Type: Report
System: The UNT Digital Library
NIST cooperative laboratory for OSI routing technology (open access)

NIST cooperative laboratory for OSI routing technology

This document is one of two reports on the Integrated ISIS protocol. Required by the IAB/IESG in order for an Internet routing protocol to advance to Draft Standard Status. Integrated ISIS is an Interior Gateway Protocol and is designed to carry both IP and ISO CLNP routing information. Integrated ISIS is currently designated as a Proposed Standard. The protocol was first published in RFC 1195. Internet Draft was published subsequently to RFC 1195 and documents the current version of the protocol. This report documents experience with Integrated ISIS. This includes reports on interoperability testing, field experience and the current state of Integrated ISIS implementations. It also presents a summary of the Integrated ISIS Management Information Base (MIB), and a summary of the Integrated ISIS authentication mechanism.
Date: May 23, 1994
Creator: Montgomery, D.
Object Type: Report
System: The UNT Digital Library
Non-inductive Solenoid-less Plasma Current Start-up in NSTX Using Transient CHI (open access)

Non-inductive Solenoid-less Plasma Current Start-up in NSTX Using Transient CHI

Coaxial Helicity Injection (CHI) has been successfully used in the National Spherical Torus Experiment (NSTX) for a demonstration of closed flux current generation without the use of the central solenoid. The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. CHI is a promising candidate for solenoid-free plasma startup in a ST. The method has now produced closed flux current up to 160 kA verifying the high current capability of this method in a large ST built with conventional tokamak components.
Date: May 23, 2007
Creator: Raman, R.; Jarboe, T. R.; Nelson, B. A.; Bell, M. G.; Ono, M.; Bigelow, T. et al.
Object Type: Report
System: The UNT Digital Library
Characterization of Cathode Materials for Rechargeable Lithium Batteries using Synchrotron Based In Situ X-ray Techniques (open access)

Characterization of Cathode Materials for Rechargeable Lithium Batteries using Synchrotron Based In Situ X-ray Techniques

The emergence of portable telecommunication, computer equipment and ultimately hybrid electric vehicles has created a substantial interest in manufacturing rechargeable batteries that are less expensive, non-toxic, operate for longer time, small in size and weigh less. Li-ion batteries are taking an increasing share of the rechargeable battery market. The present commercial battery is based on a layered LiCoO{sub 2} cathode and a graphitized carbon anode. LiCoO{sub 2} is expensive but it has the advantage being easily manufactured in a reproducible manner. Other low cost layered compounds such as LiNiO{sub 2}, LiNi{sub 0.85}Co{sub 0.15}O{sub 2} or cubic spinels such as LiMn{sub 2}O{sub 4} have been considered. However, these suffer from cycle life and thermal stability problems. Recently, some battery companies have demonstrated a new concept of mixing two different types of insertion compounds to make a composite cathode, aimed at reducing cost and improving self-discharge. Reports clearly showed that this blending technique can prevent the decline in ·capacity caused by cycling or storage at elevated temperatures. However, not much work has been reported on the charge-discharge characteristics and phase transitions for these composite cathodes. Understanding the structure and structural changes of electrode materials during the electrochemical cycling is the key to …
Date: May 23, 2007
Creator: Yang, Xiao-Qing
Object Type: Report
System: The UNT Digital Library
Anisotropic Pressure, Transport, and Shielding of Magnetic Perturbations (open access)

Anisotropic Pressure, Transport, and Shielding of Magnetic Perturbations

We compute the effect on a tokamak of applying a nonaxisymmetric magnetic perturbation δΒ. An equilibrium with scalar pressure p yields zero net radial current, and therefore zero torque. Thus, the usual approach, which assumes scalar pressure, is not self-consistent, and masks the close connection which exists between that radial current and the in-surface currents, which provide shielding or amplification of δΒ. Here, we analytically compute the pressure anisoptropy, anisoptropy, pll, p⊥ ≠ p, and from this, both the radial and in-surface currents. The surface-average of the radial current recovers earlier expressions for ripple transport, while the in-surface currents provide an expression for the amount of self-consistent shielding the plasma provides.
Date: May 23, 2008
Creator: Boozer, H.E. Mynick and A.H.
Object Type: Report
System: The UNT Digital Library
NOTE ON TRANSISTORS FOR AVALANCHE-MODE OPERATION (open access)

NOTE ON TRANSISTORS FOR AVALANCHE-MODE OPERATION

None
Date: May 23, 1962
Creator: Miller,Harold W. & Kerns, Quentin A.
Object Type: Report
System: The UNT Digital Library
Computation of the bounce-average code (open access)

Computation of the bounce-average code

The bounce-average computer code simulates the two-dimensional velocity transport of ions in a mirror machine. The code evaluates and bounce-averages the collision operator and sources along the field line. A self-consistent equilibrium magnetic field is also computed using the long-thin approximation. Optionally included are terms that maintain ..mu.., J invariance as the magnetic field changes in time. The assumptions and analysis that form the foundation of the bounce-average code are described. When references can be cited, the required results are merely stated and explained briefly. A listing of the code is appended.
Date: May 23, 1977
Creator: Cutler, T. A.; Pearlstein, L. D. & Rensink, M. E.
Object Type: Report
System: The UNT Digital Library