2012 Molecular Basis of Microbial One-Carbon Metabolism Gordon Research Conferences and Gordon Research Seminar, August 4-10,2012 (open access)

2012 Molecular Basis of Microbial One-Carbon Metabolism Gordon Research Conferences and Gordon Research Seminar, August 4-10,2012

The 2012 Gordon Conference will present and discuss cutting-edge research in the field of microbial metabolism of C1 compounds. The conference will feature the roles and application of C1 metabolism in natural and synthetic systems at scales from molecules to ecosystems. The conference will stress molecular aspects of the unique metabolism exhibited by autotrophic bacteria, methanogens, methylotrophs, aerobic and anaerobic methanotrophs, and acetogens.
Date: August 10, 2012
Creator: Hanson, Thomas
Object Type: Article
System: The UNT Digital Library
High Temperature coatings based on {beta}-NiAI (open access)

High Temperature coatings based on {beta}-NiAI

High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB{sub 2} composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.
Date: July 10, 2012
Creator: Severs, Kevin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Engineering Bacteria for Efficient Fuel Production (open access)

Engineering Bacteria for Efficient Fuel Production

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses engineering a microorganism to create a liquid fuel from hydrogen and carbon dioxide as part of the "Novel Biological Conversion of Hydrogen and Carbon Dioxide Directly into Free Fatty Acids" project.
Date: May 10, 2012
Creator: OPX Biotechnologies
Object Type: Text
System: The UNT Digital Library
Spatially Resolved Study of Backscattering in the Quantum Spin Hall State (open access)

Spatially Resolved Study of Backscattering in the Quantum Spin Hall State

None
Date: December 10, 2012
Creator: Konig, Markus; Baenninger, Matthias; Garcia, Andrei G. F.; Harjee, Nahid; Pruitt, Beth L.; Ames, C. et al.
Object Type: Article
System: The UNT Digital Library
Biofuels from Solar Energy and Bacteria (open access)

Biofuels from Solar Energy and Bacteria

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses the conversion of carbon dioxide into liquid fuels as part of the "Electrofuels Via Direct Electron Transfer from Electrodes to Microbes" project.
Date: May 10, 2012
Creator: University of Massachusetts Amherst
Object Type: Text
System: The UNT Digital Library
Observation of Ion Acceleration and Heating during Collisionless Magnetic Reconnection in a Laboratory Plasma (open access)

Observation of Ion Acceleration and Heating during Collisionless Magnetic Reconnection in a Laboratory Plasma

The ion dynamics in a collisionless magnetic reconnection layer are studied in a laboratory plasma. The measured in-plane plasma potential profile, which is established by electrons accelerated around the electron diffusion region, shows a saddle-shaped structure that is wider and deeper towards the outflow direction. This potential structure ballistically accelerates ions near the separatrices toward the outflow direction. Ions are heated as they travel into the high pressure downstream region.
Date: December 10, 2012
Creator: Jongsoo Yoo, Masaaki Yamada, HantaoJi and Clayton E. Myers
Object Type: Report
System: The UNT Digital Library
FUNDAMENTAL ENVIRONMENTAL REACTIVITY TESTING AND ANALYSIS OF THE HYDROGEN STORAGE MATERIAL 2LIBH4 MGH2 (open access)

FUNDAMENTAL ENVIRONMENTAL REACTIVITY TESTING AND ANALYSIS OF THE HYDROGEN STORAGE MATERIAL 2LIBH4 MGH2

While the storage of hydrogen for portable and stationary applications is regarded as critical in bringing PEM fuel cells to commercial acceptance, little is known of the environmental exposure risks posed in utilizing condensed phase chemical storage options as in complex hydrides. It is thus important to understand the effect of environmental exposure of metal hydrides in the case of accident scenarios. Simulated tests were performed following the United Nations standards to test for flammability and water reactivity in air for a destabilized lithium borohydride and magnesium hydride system in a 2 to 1 molar ratio respectively. It was determined that the mixture acted similarly to the parent, lithium borohydride, but at slower rate of reaction seen in magnesium hydride. To quantify environmental exposure kinetics, isothermal calorimetry was utilized to measure the enthalpy of reaction as a function of exposure time to dry and humid air, and liquid water. The reaction with liquid water was found to increase the heat flow significantly during exposure compared to exposure in dry or humid air environments. Calorimetric results showed the maximum normalized heat flow the fully charged material was 6 mW/mg under liquid phase hydrolysis; and 14 mW/mg for the fully discharged material …
Date: January 10, 2012
Creator: James, C.; Anton, D.; Cortes-Concepcion, J.; Brinkman, K. & Gray, J.
Object Type: Article
System: The UNT Digital Library
2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies (open access)

2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

This Research is about Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies which presents a preliminary model of the three-dimensional seismic structure of the Iran region.
Date: September 10, 2012
Creator: Wetovsky, Marvin A.; Anderson, Dale; Arrowsmith, Stephen J.; Begnaud, Michael L.; Hartse, Hans E.; Maceira, Monica et al.
Object Type: Article
System: The UNT Digital Library
Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry (open access)

Bootstrap Current for the Edge Pedestal Plasma in a Diverted Tokamak Geometry

The edge bootstrap current plays a critical role in the equilibrium and stability of the steep edge pedestal plasma. The pedestal plasma has an unconventional and difficult neoclassical property, as compared with the core plasma. It has a narrow passing particle region in velocity space that can be easily modified or destroyed by Coulomb collisions. At the same time, the edge pedestal plasma has steep pressure and electrostatic potential gradients whose scale-lengths are comparable with the ion banana width, and includes a magnetic separatrix surface, across which the topological properties of the magnetic field and particle orbits change abruptly. A driftkinetic particle code XGC0, equipped with a mass-momentum-energy conserving collision operator, is used to study the edge bootstrap current in a realistic diverted magnetic field geometry with a self-consistent radial electric field. When the edge electrons are in the weakly collisional banana regime, surprisingly, the present kinetic simulation confirms that the existing analytic expressions [represented by O. Sauter et al. , Phys. Plasmas 6 , 2834 (1999)] are still valid in this unconventional region, except in a thin radial layer in contact with the magnetic separatrix. The agreement arises from the dominance of the electron contribution to the bootstrap current …
Date: August 10, 2012
Creator: Koh, S.; Chang, C. S.; Ku, S.; Menard, J. E.; Weitzner, H. & Choe, W.
Object Type: Report
System: The UNT Digital Library
Woltjer-Taylor State Without Taylor's Conjecture-Plasma Relaxation at all Wavelengths (open access)

Woltjer-Taylor State Without Taylor's Conjecture-Plasma Relaxation at all Wavelengths

In astrophysical and laboratory plasmas, it has been discovered that plasmas relax towards the well-known Woltjer-Taylor state specified by ∇ x B = αB for a constant α . To explain how such a relaxed state is reached, Taylor developed his famous relaxation theory based on the conjecture that the relaxation is dominated by short wavelength fluctuations. However, there is no conclusive experimental and numerical evidence to support Taylor's conjecture. A new theory is developed, which predicts that the system will evolve towards the Woltjer-Taylor state for an arbitrary fluctuation spectrum.
Date: October 10, 2012
Creator: Qin, Hong; Liu, Wandong; Li, Hong & Squire, Jonathan
Object Type: Report
System: The UNT Digital Library
FINAL REPORT FOR DE-FG02-03ER46071 ENTITLED, "UNDERSTANDING FOAM RHEOLOGY FROM THE MICROSCOPIC TO THE MACROSCOPIC SCALE" (open access)

FINAL REPORT FOR DE-FG02-03ER46071 ENTITLED, "UNDERSTANDING FOAM RHEOLOGY FROM THE MICROSCOPIC TO THE MACROSCOPIC SCALE"

This research effort is focused on understanding the mechanical response of foams, and other complex fluids, from the microscopic to the macroscopic level. The research uses a model two-dimensional system: bubble rafts. Bubble rafts are a single layer of gas bubbles with liquid walls that float on a water surface. The work involves studies of the macroscopic response of foam under various conditions of external forcing, mesoscopic studies of bubble motion, and systematic variations of the microscopic details of the system. In addition to characterizing the specific properties of the bubble raft, a second aim of the research is to provide experimental tests of various general theories that have recently been developed to characterize complex fluids. Primarily, the focus is on testing the proposed jamming phase diagram paradigm. This paradigm suggests that a general “jammed” state of matter exists and is common to a wide range of systems, including foam, colloids, granular matter, glasses, and emulsions. Therefore,we have extended our research in two directions. First, we have included studies of plastic bead rafts. These are systems of plastic beads floating on the air-water interface. The advantage of plastic beads is that they do not pop, so they can be studied …
Date: January 10, 2012
Creator: Dennin, Michael
Object Type: Report
System: The UNT Digital Library
A 4.2 GS/sec. Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback (open access)

A 4.2 GS/sec. Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback

A 4.2 GS/sec. beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in syn- chronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20-1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals, selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. The successful use of this system for SPS MD measurements in 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion.
Date: July 10, 2012
Creator: Fox, John
Object Type: Article
System: The UNT Digital Library
GENETIC ANALYSIS OF ABSCISIC ACID BIOSYNTHESIS (open access)

GENETIC ANALYSIS OF ABSCISIC ACID BIOSYNTHESIS

The carotenoid cleavage dioxygenases (CCD) catalyze synthesis of a variety of apo-carotenoid secondary metabolites in plants, animals and bacteria. In plants, the reaction catalyzed by the 11, 12, 9-cis-epoxy carotenoid dioxygenase (NCED) is the first committed and key regulated step in synthesis of the plant hormone, abscisic acid (ABA). ABA is a key regulator of plant stress responses and has critical functions in normal root and seed development. The molecular mechanisms responsible for developmental control of ABA synthesis in plant tissues are poorly understood. Five of the nine CCD genes present in the Arabidopsis genome encode NCED's involved in control of ABA synthesis in the plant. This project is focused on functional analysis of these five AtNCED genes as a key to understanding developmental regulation of ABA synthesis and dissecting the role of ABA in plant development. For this purpose, the project developed a comprehensive set of gene knockouts in the AtNCED genes that facilitate genetic dissection of ABA synthesis. These mutants were used in combination with key molecular tools to address the following specific objectives: (1) the role of ABA synthesis in root development; (2) developmental control of ABA synthesis in seeds; (3) analysis of ATNCED over-expressers; (4) preliminary …
Date: January 10, 2012
Creator: R, MCCARTY D
Object Type: Report
System: The UNT Digital Library
Analysis of ultra-narrow ferromagnetic domain walls (open access)

Analysis of ultra-narrow ferromagnetic domain walls

New materials with high magnetic anisotropy will have domains separated by ultra-narrow ferromagnetic walls with widths on the order of a few unit cells, approaching the limit where the elastic continuum approximation often used in micromagnetic simulations is accurate. The limits of this approximation are explored, and the static and dynamic interactions with intrinsic crystalline defects and external driving #12;elds are modeled. The results developed here will be important when considering the stability of ultra-high-density storage media.
Date: January 10, 2012
Creator: Jenkins, Catherine & Paul, David
Object Type: Article
System: The UNT Digital Library
Fuel from Bacteria (open access)

Fuel from Bacteria

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to genetically modify bacteria to generate Butanol from carbon dioxide (project title "Bioconversion of Carbon Dioxide to Biofuels by Facultatively Autotrophic Hydrogen Bacteria") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 10, 2012
Creator: Ohio State University
Object Type: Text
System: The UNT Digital Library
Lithium As Plasma Facing Component for Magnetic Fusion Research (open access)

Lithium As Plasma Facing Component for Magnetic Fusion Research

The use of lithium in magnetic fusion confinement experiments started in the 1990's in order to improve tokamak plasma performance as a low-recycling plasma-facing component (PFC). Lithium is the lightest alkali metal and it is highly chemically reactive with relevant ion species in fusion plasmas including hydrogen, deuterium, tritium, carbon, and oxygen. Because of the reactive properties, lithium can provide strong pumping for those ions. It was indeed a spectacular success in TFTR where a very small amount (~ 0.02 gram) of lithium coating of the PFCs resulted in the fusion power output to improve by nearly a factor of two. The plasma confinement also improved by a factor of two. This success was attributed to the reduced recycling of cold gas surrounding the fusion plasma due to highly reactive lithium on the wall. The plasma confinement and performance improvements have since been confirmed in a large number of fusion devices with various magnetic configurations including CDX-U/LTX (US), CPD (Japan), HT-7 (China), EAST (China), FTU (Italy), NSTX (US), T-10, T-11M (Russia), TJ-II (Spain), and RFX (Italy). Additionally, lithium was shown to broaden the plasma pressure profile in NSTX, which is advantageous in achieving high performance H-mode operation for tokamak reactors. …
Date: September 10, 2012
Creator: Ono, Masayuki
Object Type: Report
System: The UNT Digital Library
Final Scientific/Technical Report Grant Title: Use of Arm Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction This Is a Collaborative Project With the Nasa Gsfc Project of Dr. A. Marshak and W. Wiscombe (Pis). This Report Covers Bu Activities From February 2011 to June 2011 and Bu "âœNo-Cost Extension" Activities From June 2011 to June 2012. This Report Summarizes Results That Complement a Final Technical Report Submitted by the Pis in 2011. (open access)

Final Scientific/Technical Report Grant Title: Use of Arm Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction This Is a Collaborative Project With the Nasa Gsfc Project of Dr. A. Marshak and W. Wiscombe (Pis). This Report Covers Bu Activities From February 2011 to June 2011 and Bu "âœNo-Cost Extension" Activities From June 2011 to June 2012. This Report Summarizes Results That Complement a Final Technical Report Submitted by the Pis in 2011.

Main results are summarized for work in these areas: spectrally-invariant approximation within atmospheric radiative transfer; spectral invariance of single scattering albedo for water droplets and ice crystals at weakly absorbing wavelengths; seasonal changes in leaf area of Amazon forests from leaf flushing and abscission; and Cloud droplet size and liquid water path retrievals from zenith radiance measurements.
Date: September 10, 2012
Creator: Knyazikhin, Y.
Object Type: Report
System: The UNT Digital Library
Low Cost Chemical Feedstocks Using an Improved and Energy Efficient Natural Gas Liquid (NGL) Removal Process, Final Technical Report (open access)

Low Cost Chemical Feedstocks Using an Improved and Energy Efficient Natural Gas Liquid (NGL) Removal Process, Final Technical Report

The overall objective of this project is to develop a new low-cost and energy efficient Natural Gas Liquid (NGL) recovery process - through a combination of theoretical, bench-scale and pilot-scale testing - so that it could be offered to the natural gas industry for commercialization. The new process, known as the IROA process, is based on U.S. patent No. 6,553,784, which if commercialized, has the potential of achieving substantial energy savings compared to currently used cryogenic technology. When successfully developed, this technology will benefit the petrochemical industry, which uses NGL as feedstocks, and will also benefit other chemical industries that utilize gas-liquid separation and distillation under similar operating conditions. Specific goals and objectives of the overall program include: (i) collecting relevant physical property and Vapor Liquid Equilibrium (VLE) data for the design and evaluation of the new technology, (ii) solving critical R&D issues including the identification of suitable dehydration and NGL absorbing solvents, inhibiting corrosion, and specifying proper packing structure and materials, (iii) designing, construction and operation of bench and pilot-scale units to verify design performance, (iv) computer simulation of the process using commercial software simulation platforms such as Aspen-Plus and HYSYS, and (v) preparation of a commercialization plan and …
Date: August 10, 2012
Creator: Meyer, Howard, S. & Lu, Yingzhong
Object Type: Report
System: The UNT Digital Library
Accelerating Atomic Orbital-based Electronic Structure Calculation via Pole Expansion plus Selected Inversion (open access)

Accelerating Atomic Orbital-based Electronic Structure Calculation via Pole Expansion plus Selected Inversion

We describe how to apply the recently developed pole expansion plus selected inversion (PEpSI) technique to Kohn-Sham density function theory (DFT) electronic structure calculations that are based on atomic orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and eigenvectors of the Kohn-Sham Hamiltonian. We also show how to update the chemical potential without using Kohn-Sham eigenvalues. The advantage of using PEpSI is that it has a much lower computational complexity than that associated with the matrix diagonalization procedure. We demonstrate the performance gain by comparing the timing of PEpSI with that of diagonalization on insulating and metallic nanotubes. For these quasi-1D systems, the complexity of PEpSI is linear with respect to the number of atoms. This linear scaling can be observed in our computational experiments when the number of atoms in a nanotube is larger than a few hundreds. Both the wall clock time and the memory requirement of PEpSI is modest. This makes it even possible to perform Kohn-Sham DFT calculations for 10,000-atom nanotubes on a single processor. We also show that the use of PEpSI does not lead to loss of accuracy required in …
Date: February 10, 2012
Creator: Lin, Lin; Chen, Mohan; Yang, Chao & He, Lixin
Object Type: Article
System: The UNT Digital Library
2012 VIBRATIONAL SPECTROSCOPY GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012 (open access)

2012 VIBRATIONAL SPECTROSCOPY GORDON RESEARCH CONFERENCE, AUGUST 5-10, 2012

The Vibrational Spectroscopy conference brings together experimentalists and theoreticians working at the frontiers of modern vibrational spectroscopy, with a special emphasis on spectroscopies that probe the structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear, and multidimensional spectroscopies. The conference highlights both the application of these techniques in chemistry, materials, biology, the environment, and medicine as well as the development of theoretical models that enable one to connect spectroscopic signatures to underlying molecular motions including chemical reaction dynamics. The conference goal is to advance the field of vibrational spectroscopy by bringing together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules, nanomaterials, and environmental systems.
Date: August 10, 2012
Creator: Geiger, Franz
Object Type: Article
System: The UNT Digital Library
Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab (open access)

Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.
Date: May 10, 2012
Creator: Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S. & Rakhno, I.
Object Type: Article
System: The UNT Digital Library
Electric Vehicle Batteries (open access)

Electric Vehicle Batteries

Advanced Research Projects Agency-Energy project sheet summarizing general information about the 10 projects that are a part of the Batteries for Electrical Energy Storage in Transportation (BEEST) program including project goals, innovation needs, and potential impacts.
Date: May 10, 2012
Creator: United States. Advanced Research Projects Agency-Energy.
Object Type: Text
System: The UNT Digital Library
Advances in NIF Shock Timing Experiments (open access)

Advances in NIF Shock Timing Experiments

None
Date: July 10, 2012
Creator: Robey, H. F.; Celliers, P. M.; Moody, J. D. & MacKinnon, A. J.
Object Type: Article
System: The UNT Digital Library
Biofuels from Bacteria, Electricity, and CO2 (open access)

Biofuels from Bacteria, Electricity, and CO2

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Electrofuels program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses combining ammonia and bacteria to produce liquid fuel as part of the "Biofuels from CO2 Using Ammonia or Iron-Oxidizing Bacteria in Reverse Microbial Fuel Cells" project.
Date: May 10, 2012
Creator: Columbia University
Object Type: Text
System: The UNT Digital Library