In-situ spectro-microscopy on organic films: Mn-Phthalocyanine on Ag(100) (open access)

In-situ spectro-microscopy on organic films: Mn-Phthalocyanine on Ag(100)

Metal phthalocyanines are attracting significant attention, owing to their potential for applications in chemical sensors, solar cells and organic magnets. As the electronic properties of molecular films are determined by their crystallinity and molecular packing, the optimization of film quality is important for improving the performance of organic devices. Here, we present the results of in situ low-energy electron microscopy / photoemission electron microscopy (LEEM/PEEM) studies of incorporation-limited growth [1] of manganese-phthalocyanine (MnPc) on Ag(100) surfaces. MnPc thin films were grown on both, bulk Ag(100) surface and thin Ag(100)/Fe(100) films, where substrate spin-polarized electronic states can be modified through tuning the thickness of the Ag film [2]. We also discuss the electronic structure and magnetic ordering in MnPc thin films, investigated by angle- and spin-resolved photoemission spectroscopy.
Date: August 18, 2013
Creator: A., Al-Mahboob; Vescovo, E. & Sadowski, J.T.
Object Type: Article
System: The UNT Digital Library
INTERIM REPORT--INDEPENDENT VERIFICATION SURVEY OF SECTION 3, SURVEY UNITS 1, 4 AND 5 EXCAVATED SURFACES, WHITTAKER CORPORATION, REYNOLDS INDUSTRIAL PARK, TRANSFER, PENNSYLVANIA DCN: 5002-SR-04-0" (open access)

INTERIM REPORT--INDEPENDENT VERIFICATION SURVEY OF SECTION 3, SURVEY UNITS 1, 4 AND 5 EXCAVATED SURFACES, WHITTAKER CORPORATION, REYNOLDS INDUSTRIAL PARK, TRANSFER, PENNSYLVANIA DCN: 5002-SR-04-0"

At Pennsylvania Department of Environmental Protection's request, ORAU's IEAV program conducted verification surveys on the excavated surfaces of Section 3, SUs 1, 4, and 5 at the Whittaker site on March 13 and 14, 2013. The survey activities included visual inspections, gamma radiation surface scans, gamma activity measurements, and soil sampling activities. Verification activities also included the review and assessment of the licensee�s project documentation and methodologies. Surface scans identified four areas of elevated direct gamma radiation distinguishable from background; one area within SUs 1 and 4 and two areas within SU5. One area within SU5 was remediated by removing a golf ball size piece of slag while ORAU staff was onsite. With the exception of the golf ball size piece of slag within SU5, a review of the ESL Section 3 EXS data packages for SUs 1, 4, and 5 indicated that these locations of elevated gamma radiation were also identified by the ESL gamma scans and that ESL personnel performed additional investigations and soil sampling within these areas. The investigative results indicated that the areas met the release criteria.
Date: April 18, 2013
Creator: ADAMS, WADE C
Object Type: Report
System: The UNT Digital Library
A Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp-bar Collisions at sqrt(s) = 1.96 TeV (open access)

A Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp-bar Collisions at sqrt(s) = 1.96 TeV

None
Date: January 18, 2013
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Fermi-LAT Study of Gamma-Ray Emission in the Direction of Supernova Remnant W49B (open access)

Fermi-LAT Study of Gamma-Ray Emission in the Direction of Supernova Remnant W49B

None
Date: June 18, 2013
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G. et al.
Object Type: Article
System: The UNT Digital Library
Final Pantex Report - 2006 [Phase 1 plan for assessment of Former Workers at the Pantex Facility] (open access)

Final Pantex Report - 2006 [Phase 1 plan for assessment of Former Workers at the Pantex Facility]

The purpose of this project was to develop a Phase 1 plan for assessment of Former Workers at the Pantex Facility in Amarillo, TX and to determine the suitability to start a medical surveillance program among former workers for this site.
Date: July 18, 2013
Creator: Abdo, Ronna
Object Type: Report
System: The UNT Digital Library
Response of NSTX Liquid Lithium divertor to High Heat Loads (open access)

Response of NSTX Liquid Lithium divertor to High Heat Loads

Samples of the NSTX Liquid Lithium Divertor (LLD) with and without an evaporative Li coating were directly exposed to a neutral beam ex-situ at a power of ~1.5 MW/m2 for 1-3 seconds. Measurements of front face and bulk sample temperature were obtained. Predictions of temperature evolution were derived from a 1D heat flux model. No macroscopic damage occurred when the "bare" sample was exposed to the beam but microscopic changes to the surface were observed. The Li-coated sample developed a lithium hydroxide (LiOH) coating, which did not change even when the front face temperature exceeded the pure Li melting point. These results are consistent with the lack of damage to the LLD surface and imply that heating alone may not expose pure liquid Li if the melting point of surface impurities is not exceeded. This suggests that flow and heat are needed for future PFCs requiring a liquid Li surface. __________________________________________________
Date: July 18, 2012
Creator: Abrams, Tyler; Kallman, J; Kaitaa, R; Foley, E L; Grayd, T K; Kugel, H et al.
Object Type: Article
System: The UNT Digital Library
Searches for Cosmic-Ray Electron Anisotropies with the Fermi Large Area Telescope (open access)

Searches for Cosmic-Ray Electron Anisotropies with the Fermi Large Area Telescope

None
Date: June 18, 2013
Creator: Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz et al.
Object Type: Article
System: The UNT Digital Library
Tune Evaluation From Phased BPM Turn-By-Turn Data (open access)

Tune Evaluation From Phased BPM Turn-By-Turn Data

In fast ramping synchrotrons like the Fermilab Booster the conventional methods of betatron tune evaluation from the turn-by-turn data may not work due to rapid changes of the tunes (sometimes in a course of a few dozens of turns) and a high level of noise. We propose a technique based on phasing of signals from a large number of BPMs which significantly increases the signal to noise ratio. Implementation of the method in the Fermilab Booster control system is described and some measurement results are presented.
Date: May 18, 2010
Creator: Alexahin, Y.; Gianfelice-Wendt, E. & Marsh, W.
Object Type: Article
System: The UNT Digital Library
Stuff Moving Through Other Stuff - For Energy (open access)

Stuff Moving Through Other Stuff - For Energy

Representing the Understanding Charge Separation and Transfer at Interfaces in Energy Materials (EFRC:CST), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. Understanding Charge Separation and Transfer at Interfaces in Energy Materials (EFRC:CST), is focused on advancing the understanding and design of nanostructured molecular materials for organic photovoltaic (OPV) and electrical energy storage (EES) applications.
Date: July 18, 2013
Creator: All EFRC effort,
Object Type: Text
System: The UNT Digital Library
The evolution of ion charge states in cathodic vacuum arc plasmas: a review (open access)

The evolution of ion charge states in cathodic vacuum arc plasmas: a review

Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.
Date: December 18, 2011
Creator: Anders, Andre
Object Type: Article
System: The UNT Digital Library
The SEMATECH Berkeley MET: extending EUV learning to 16-nm half pitch (open access)

The SEMATECH Berkeley MET: extending EUV learning to 16-nm half pitch

Several high-performing resists identified in the past two years have been exposed at the 0.3-numerical-aperture (NA) SEMATECH Berkeley Microfield Exposure Tool (BMET) with an engineered dipole illumination optimized for 18-nm half pitch. Five chemically amplified platforms were found to support 20-nm dense patterning at a film thickness of approximately 45 nm. At 19-nm half pitch, however, scattered bridging kept all of these resists from cleanly resolving larger areas of dense features. At 18-nm half pitch, none of the resists were are able to cleanly resolve a single line within a bulk pattern. With this same illumination a directly imageable metal oxide hardmask showed excellent performance from 22-nm half pitch to 17-nm half pitch, and good performance at 16-nm half pitch, closely following the predicted aerial image contrast. This indicates that observed limitations of the chemically amplified resists are indeed coming from the resist and not from a shortcoming of the exposure tool. The imageable hardmask was also exposed using a Pseudo Phase-Shift-Mask technique and achieved clean printing of 15-nm half pitch lines and modulation all the way down to the theoretical 12.5-nm resolution limit of the 0.3-NA SEMATECH BMET.
Date: March 18, 2011
Creator: Anderson, Christopher N.; Baclea-an, Lorie Mae; Denham, Paul E.; George, Simi; Goldberg, Kenneth A.; Jones, Michael et al.
Object Type: Article
System: The UNT Digital Library
Benefits to the U.S. from Physicists Working at Accelerators Overseas (open access)

Benefits to the U.S. from Physicists Working at Accelerators Overseas

None
Date: December 18, 2013
Creator: Anderson, Jacob; Brock, Raymond; Gershtein, Yuri; Hadley, Nicholas; Harrison, Michael; Narain, Meenakshi et al.
Object Type: Article
System: The UNT Digital Library
Magnetic Measurement Results of the LCLS Undulator Quadrupoles (open access)

Magnetic Measurement Results of the LCLS Undulator Quadrupoles

This note details the magnetic measurements and the magnetic center fiducializations that were performed on all of the thirty-six LCLS undulator quadrupoles. Temperature rise, standardization reproducibility, vacuum chamber effects and magnetic center reproducibility measurements are also presented. The Linac Coherent Light Source (LCLS) undulator beam line has 33 girders, each with a LCLS undulator quadrupole which focuses and steers the beam through the beam line. Each quadrupole has main quadrupole coils, as well as separate horizontal and vertical trim coils. Thirty-six quadrupoles, thirty-three installed and three spares were, manufactured for the LCLS undulator system and all were measured to confirm that they met requirement specifications for integrated gradient, harmonics and for magnetic center shifts after current changes. The horizontal and vertical dipole trims of each quadrupole were similarly characterized. Each quadrupole was also fiducialized to its magnetic center. All characterizing measurements on the undulator quads were performed with their mirror plates on and after a standardization of three cycles from -6 to +6 to -6 amps. Since the undulator quadrupoles could be used as a focusing or defocusing magnet depending on their location, all quadrupoles were characterized as focusing and as defocusing quadrupoles. A subset of the undulator quadrupoles were …
Date: August 18, 2011
Creator: Anderson, Scott; Caban, Keith; Nuhn, Heinz-Dieter; Reese, Ed & Wolf, Zachary
Object Type: Report
System: The UNT Digital Library
A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic (open access)

A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic

Topic models have been used successfully for a variety of problems, often in the form of application-specific extensions of the basic Latent Dirichlet Allocation (LDA) model. Because deriving these new models in order to encode domain knowledge can be difficult and time-consuming, we propose the Fold-all model, which allows the user to specify general domain knowledge in First-Order Logic (FOL). However, combining topic modeling with FOL can result in inference problems beyond the capabilities of existing techniques. We have therefore developed a scalable inference technique using stochastic gradient descent which may also be useful to the Markov Logic Network (MLN) research community. Experiments demonstrate the expressive power of Fold-all, as well as the scalability of our proposed inference method.
Date: January 18, 2011
Creator: Andrzejewski, D.; Zhu, X.; Craven, M. & Recht, B.
Object Type: Article
System: The UNT Digital Library
LIFE Delivery Plan (open access)

LIFE Delivery Plan

None
Date: April 18, 2011
Creator: Anklam, T M
Object Type: Report
System: The UNT Digital Library
The Impact of Camera Optical Alignments on Weak Lensing Measures for the Dark Energy Survey (open access)

The Impact of Camera Optical Alignments on Weak Lensing Measures for the Dark Energy Survey

None
Date: March 18, 2013
Creator: Antonik, Michelle L.; Bacon, David J.; Bridle, Sarah; Doel, Peter; Brooks, David; Worswick, Sue et al.
Object Type: Article
System: The UNT Digital Library
Year 4 Report Multiplex Assay Development for Detection of Potential Bioterrorism Agents in Food Matrices (open access)

Year 4 Report Multiplex Assay Development for Detection of Potential Bioterrorism Agents in Food Matrices

None
Date: June 18, 2013
Creator: Arani, P N
Object Type: Report
System: The UNT Digital Library
The BaBar Detector: Upgrades, Operation and Performance (open access)

The BaBar Detector: Upgrades, Operation and Performance

None
Date: December 18, 2013
Creator: Aubert, Bernard
Object Type: Article
System: The UNT Digital Library
How to Store Energy Fast (open access)

How to Store Energy Fast

Representing the Molecularly Engineered Energy Materials (MEEM), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of MEEM, using inexpensive custom-designed molecular building blocks, aims to create revolutionary new materials with self-assembled multi-scale architectures that will enable high performing energy generation and storage applications.
Date: July 18, 2013
Creator: Augustyn, Veronica; Ko, Jesse & Rauda, Iris
Object Type: Text
System: The UNT Digital Library
Management Of Experiments And Data At The National Ignition Facility (open access)

Management Of Experiments And Data At The National Ignition Facility

Experiments, or 'shots', conducted at the National Ignition Facility (NIF) are discrete events that occur over a very short time frame (tens of nanoseconds) separated by many hours. Each shot is part of a larger campaign of shots to advance scientific understanding in high-energy-density physics. In one campaign, scientists use energy from the 192-beam, 1.8-Megajoule pulsed laser in the NIF system to symmetrically implode a hydrogen-filled target, thereby creating conditions similar to the interior of stars in a demonstration of controlled fusion. Each NIF shot generates gigabytes of data from over 30 diagnostics that measure optical, x-ray, and nuclear phenomena from the imploding target. We have developed systems to manage all aspects of the shot cycle. Other papers will discuss the control of the lasers and targets, while this paper focuses on the setup and management of campaigns and diagnostics. Because of the low duty cycle of shots, and the thousands of adjustments for each shot (target type, composition, shape; laser beams used, their power profiles, pointing; diagnostic systems used, their configuration, calibration, settings) it is imperative that we accurately define all equipment prior to the shot. Following the shot, and capture of the data by the automatic control system, …
Date: March 18, 2011
Creator: Azevedo, S; Casey, A; Beeler, R; Bettenhausen, R.; Bond, E.; Chandrasekaran, H. et al.
Object Type: Article
System: The UNT Digital Library
Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction (open access)

Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction

None
Date: January 18, 2013
Creator: Aznauryan, I. G.; Bashir, A.; Braun, V.; Brodsky, S. J.; Burkert, V. D.; Chang, L. et al.
Object Type: Article
System: The UNT Digital Library
RELAP5 Application to Accident Analysis of the NIST Research Reactor (open access)

RELAP5 Application to Accident Analysis of the NIST Research Reactor

Detailed safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The time-dependent analysis of the primary system is determined with a RELAP5 transient analysis model that includes the reactor vessel, the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. A post-processing of the simulation results has been conducted to evaluate minimum critical heat flux ratio (CHFR) using the Sudo-Kaminaga correlation. Evaluations are performed for the following accidents: (1) the control rod withdrawal startup accident and (2) the maximum reactivity insertion accident. In both cases the RELAP5 results indicate that there is adequate margin to CHF and no damage to the fuel will occur because of sufficient coolant flow through the fuel channels and the negative scram reactivity insertion.
Date: March 18, 2012
Creator: Baek, J.; Cuadra Gascon, A.; Cheng, L. Y. & Diamond, D.
Object Type: Article
System: The UNT Digital Library
How are the energy waves blocked on the way from hot to cold? (open access)

How are the energy waves blocked on the way from hot to cold?

Representing the Center for Materials Science of Nuclear Fuel (CMSNF), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of CMSNF to develop an experimentally validated multi-scale computational capability for the predictive understanding of the impact of microstructure on thermal transport in nuclear fuel under irradiation, with ultimate application to UO2 as a model system
Date: July 18, 2013
Creator: Bai, Xianming; He, Lingfeng; Khafizov, Marat; Yu, Jianguo & Chernatynskiy, Aleksandr
Object Type: Text
System: The UNT Digital Library
A Note on the Convergence of the Godunov Method for Impact Problems (open access)

A Note on the Convergence of the Godunov Method for Impact Problems

None
Date: April 18, 2012
Creator: Banks, J W
Object Type: Article
System: The UNT Digital Library