12 Matching Results
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What Coexists with the Ferromagnetic Metallic Phase in Manganites?
Colossal magnetoresistance, whereby the application of a magnetic field reduces the resistivity of a manganite by orders of magnitude, is generally believed to occur because of coexisting phases. Development of a complete theory to explain the phenomenon requires that the exact nature of these phases be known. We used resonant elastic soft x-ray scattering to examine the superlattice order that exists in La{sub 0.35}Pr{sub 0.275}Ca{sub 0.375}MnO{sub 3} above and below the Curie temperature. By measuring the resonance profile of the scattered x-rays at different values of q, we disentangle the contributions of orbital order and antiferromagnetism to the scattering signal above the Curie temperature. Below the Curie temperature, we see no signal from orbital order, and only antiferromagnetism coexists with the dominant ferromagnetic metallic phase.
Date:
July 25, 2012
Creator:
Burkhardt, Mark H.; Hossain, M.A.; Sarkar, S.; Achkar, A.J.; Hawthorn, D.G.; Sutarto, R. et al.
Object Type:
Article
System:
The UNT Digital Library
Clearwater and Wineskin Sub-CAU Flow and Transport Models
None
Date:
July 25, 2012
Creator:
Carle, S F
Object Type:
Report
System:
The UNT Digital Library
Radiation Field Simulation and Estimation Algorithms for a Mobile Sensor and a Stationary Unknown Source
None
Date:
July 25, 2012
Creator:
Clark, G. A.
Object Type:
Report
System:
The UNT Digital Library
NanoComposite Stainless Steel Powder Technologies
Oak Ridge National Laboratory has been investigating a new class of Fe-based amorphous material stemming from a DARPA, Defense Advanced Research Projects Agency initiative in structural amorphous metals. Further engineering of the original SAM materials such as chemistry modifications and manufacturing processes, has led to the development of a class of Fe based amorphous materials that upon processing, devitrify into a nearly homogeneous distribution of nano sized complex metal carbides and borides. The powder material is produced through the gas atomization process and subsequently utilized by several methods; laser fusing as a coating to existing components or bulk consolidated into new components through various powder metallurgy techniques (vacuum hot pressing, Dynaforge, and hot isostatic pressing). The unique fine scale distribution of microstructural features yields a material with high hardness and wear resistance compared to material produced through conventional processing techniques such as casting while maintaining adequate fracture toughness. Several compositions have been examined including those specifically designed for high hardness and wear resistance and a composition specifically tailored to devitrify into an austenitic matrix (similar to a stainless steel) which poses improved corrosion behavior.
Date:
July 25, 2012
Creator:
DeHoff, R. & Glasgow, C. (MesoCoat, Inc.)
Object Type:
Report
System:
The UNT Digital Library
2012 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 20-25, 2012
The Gordon Research Conference on MICROBIAL STRESS RESPONSE was held at Mount Holyoke College, South Hadley, Massachusetts, July 15-20, 2012. The Conference was well-attended with 180 participants. The 2012 Microbial Stress Responses Gordon Research Conference will provide a forum for the open reporting of recent discoveries on the diverse mechanisms employed by microbes to respond to stress. Approaches range from analysis at the molecular level (how are signals perceived and transmitted to change gene expression or function) to cellular and microbial community responses. Gordon Research Conferences does not permit publication of meeting proceedings.
Date:
July 25, 2012
Creator:
Donohue, Timothy
Object Type:
Article
System:
The UNT Digital Library
Surface Engineering of Corrosion, Environmental Fracture, Cavitation & Impingement Resistant Materials
None
Date:
July 25, 2012
Creator:
Farmer, J; Rukbenchik, A; Menon, S; McNelley, T & Hackel, L
Object Type:
Article
System:
The UNT Digital Library
National Biodiesel Infrastructure Development Initiative Final Program Report
Initiative to increase acceptance of biodiesel in petroleum pipelines
Date:
July 25, 2012
Creator:
Hamilton, Jill N.; Miller, R. Lynn & Howell, Steve
Object Type:
Report
System:
The UNT Digital Library
Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report
This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal …
Date:
July 25, 2012
Creator:
Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L. & Stach, Eric A.
Object Type:
Report
System:
The UNT Digital Library
DECONTAMINATION OF PLUTONIUM FOR FLUORIDE AND CHLORIDE DURING OXALATE PRECIPITATION, FILTRATION AND CALCINATION PROCESSES
Due to analytical limitations for the determination of fluoride (F) and chloride (Cl) in a previous anion exchange study, an additional study of the decontamination of Pu from F and Cl by oxalate precipitation, filtration and calcination was performed. Anion product solution from the previous impurity study was precipitated as an oxalate, filtered, and calcined to produce an oxide for analysis by pyrohydrolysis for total Cl and F. Analysis of samples from this experiment achieved the purity specification for Cl and F for the proposed AFS-2 process. Decontamination factors (DF's) for the overall process (including anion exchange) achieved a DF of {approx}5000 for F and a DF of {approx}100 for Cl. Similar experiments where both HF and HCl were spiked into the anion product solution to a {approx}5000 {micro}g /g Pu concentration showed a DF of 5 for F and a DF of 35 for Cl across the combined precipitation-filtration-calcination process steps.
Date:
July 25, 2012
Creator:
Kyser, E.
Object Type:
Report
System:
The UNT Digital Library
Metering Plan: Monitoring Energy and Potable Water Use in PNNL EMS4 Buildings
This Plan presents progress toward the metering goals shared by all national laboratories and discusses PNNL's contemporary approach to the installation of new meters. In addition, the Plan discusses the data analysis techniques with which PNNL is working to mature using endless data streams made available as a result of increased meter deployment.
Date:
July 25, 2012
Creator:
Pope, Jason E.
Object Type:
Report
System:
The UNT Digital Library
High-harmonic Fast Wave Heating and Current Drive Results for Deuterium H-mode Plasmas in the National Spherical Torus Experiment
A critical research goal for the spherical torus (ST) program is to initiate, ramp-up, and sustain a discharge without using the central solenoid. Simulations of non-solenoidal plasma scenarios in the National Spherical Torus Experiment (NSTX) [1] predict that high-harmonic fast wave (HHFW) heating and current drive (CD) [2] can play an important roll in enabling fully non-inductive (fNI {approx} 1) ST operation. The NSTX fNI {approx} 1 strategy requires 5-6 MW of HHFW power (PRF) to be coupled into a non-inductively generated discharge [3] with a plasma current, Ip {approx} 250-350 kA, driving the plasma into an HHFW H-mode with Ip {approx} 500 kA, a level where 90 keV deuterium neutral beam injection (NBI) can heat the plasma and provide additional CD. The initial approach on NSTX has been to heat Ip {approx} 300 kA, inductively heated, deuterium plasmas with CD phased HHFW power [2], in order to drive the plasma into an H-mode with fNI {approx} 1.
Date:
July 25, 2012
Creator:
Taylor, G.; Bonoli, P. T.; Harvey, R. W.; Hosea, J. C.; Jaeger, E. F.; LeBlanc, B. P. et al.
Object Type:
Article
System:
The UNT Digital Library
Rainier Mesa/Shoshone Mountain CAU Technical Basis Agreement Document: Hydrologic Source Term
None
Date:
July 25, 2012
Creator:
Tompson, A.; Zavarin, M.; McNab, W.; Lu, C.; Shumaker, D. & Carle, S.
Object Type:
Report
System:
The UNT Digital Library