Bishop Paiute Weatherization Training Program (open access)

Bishop Paiute Weatherization Training Program

The DOE Weatherization Training Grant assisted Native American trainees in developing weatherization competencies, creating employment opportunities for Bishop Paiute tribal members in a growing field. The trainees completed all the necessary training and certification requirements and delivered high-quality weatherization services on the Bishop Paiute Reservation. Six tribal members received all three certifications for weatherization; four of the trainees are currently employed. The public benefit includes (1) development of marketable skills by low-income Native individuals, (2) employment for low-income Native individuals in a growing industry, and (3) economic development opportunities that were previously not available to these individuals or the Tribe.
Date: January 28, 2010
Creator: Hernandez, Carlos
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY (open access)

CHARACTERIZATION OF CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY

During the month of September 2008, grout core samples were collected from the Saltstone Disposal Facility, Vault 4, cell E. This grout was placed during processing campaigns in December 2007 from Deliquification, Dissolution and Adjustment Batch 2 salt solution. The 4QCY07 Waste Acceptance Criteria sample collected on 11/16/07 represents the salt solution in the core samples. Core samples were retrieved to initiate the historical database of properties of emplaced Saltstone and to demonstrate the correlation between field collected and laboratory prepared samples. Three samples were collected from three different locations. Samples were collected using a two-inch diameter concrete coring bit. In April 2009, the core samples were removed from the evacuated sample container, inspected, transferred to PVC containers, and backfilled with nitrogen. Samples furthest from the wall were the most intact cylindrically shaped cored samples. The shade of the core samples darkened as the depth of coring increased. Based on the visual inspection, sample 3-3 was selected for all subsequent analysis. The density and porosity of the Vault 4 core sample, 1.90 g/cm{sup 3} and 59.90% respectively, were comparable to values achieved for laboratory prepared samples. X-ray diffraction analysis identified phases consistent with the expectations for hydrated Saltstone. Microscopic analysis …
Date: January 28, 2010
Creator: Cozzi, A. & Duncan, A.
Object Type: Report
System: The UNT Digital Library
Effect of laser pulse shape on damage susceptibility in optical materials (open access)

Effect of laser pulse shape on damage susceptibility in optical materials

None
Date: January 28, 2010
Creator: Carr, C W; Cross, D A & DeMange, P
Object Type: Article
System: The UNT Digital Library
AN EXPERIMENTAL STUDY OF THE STABILITY OF VESSEL-SPANNING BUBBLES IN CYLINDRICAL & ANNULAR & OBROUND & AND CONICAL CONTAINERS (open access)

AN EXPERIMENTAL STUDY OF THE STABILITY OF VESSEL-SPANNING BUBBLES IN CYLINDRICAL & ANNULAR & OBROUND & AND CONICAL CONTAINERS

This report provides a summary of experiments that were performed by Fauske & Associates on the stability of vessel-spanning bubbles. The report by Fauske & Associates, An Experimental Study of the Stability of Vessel-Spanning Bubbles in Cylindrical, Annular, Obround and Conical Containers, is included in Appendix A. Results from the experiments confirm that the gravity yield parameter, Y{sub G}, correctly includes container size and can be applied to full-scale containers to predict the possibility of the formation of a stable vessel spanning bubble. The results also indicate that a vessel spanning bubble will likely form inside the STSC for KE, KW, and Settler sludges if the shear strengths of these sludges exceed 1820, 2080, and 2120 Pa, respectively. A passive mechanism installed in the STSC is effective at disrupting a rising sludge plug and preventing the sludge from plugging the vent filter or being forced out of the container. The Sludge Treatment Project for Engineered Container and Settler Sludge (EC/ST) Disposition Subproject is being conducted in two phases. Phase 1 of the EC/ST Disposition Subproject will retrieve the radioactive sludge currently stored in the K West (KW) Basin into Sludge Transport and Storage Containers (STSCs) and transport the STSCs to …
Date: January 28, 2010
Creator: TK, DHALIWAL
Object Type: Report
System: The UNT Digital Library
Maltose Biochemistry and Transport in Plant Leaves (open access)

Maltose Biochemistry and Transport in Plant Leaves

Final Technical Report for DOE grant DE-FG02-04ER15565 Maltose Biochemistry and Transport in Plant Leaves PI Thomas D. Sharkey University of Wisconsin-Madison Starch is a desirable plant product for both food and biofuel. Leaf starch is ideal for use in biofuels because it does not compete with grain starch, which is used for food. Starch is accumulated in plant leaves during the day and broken down at night. If we can manipulate leaf starch breakdown it may be possible to design a plant that provides both grain starch for food and leaf starch for biofuel. The pathway of leaf starch breakdown was not known when this work started. Preliminary evidence had shown that maltose was the primary product of leaf starch breakdown (Weise, Weber & Sharkey, 2004) and that it was metabolized by a disproportionating enzyme called amylomaltase but given the initials DPE2 (Lu & Sharkey, 2004). In this work we showed that only one form of maltose was metabolically active (Weise et al., 2005a) and that maltose was located in two different places when the amylomaltase was knocked out but only inside the chloroplast when the maltose transporter was knocked out (Lu et al., 2006a). This allowed us to estimate …
Date: January 28, 2010
Creator: Sharkey, Thomas D.
Object Type: Report
System: The UNT Digital Library
A New Approach in Advance Network Reservation and Provisioning for High-Performance Scientific Data Transfers (open access)

A New Approach in Advance Network Reservation and Provisioning for High-Performance Scientific Data Transfers

Scientific applications already generate many terabytes and even petabytes of data from supercomputer runs and large-scale experiments. The need for transferring data chunks of ever-increasing sizes through the network shows no sign of abating. Hence, we need high-bandwidth high speed networks such as ESnet (Energy Sciences Network). Network reservation systems, i.e. ESnet's OSCARS (On-demand Secure Circuits and Advance Reservation System) establish guaranteed bandwidth of secure virtual circuits at a certain time, for a certain bandwidth and length of time. OSCARS checks network availability and capacity for the specified period of time, and allocates requested bandwidth for that user if it is available. If the requested reservation cannot be granted, no further suggestion is returned back to the user. Further, there is no possibility from the users view-point to make an optimal choice. We report a new algorithm, where the user specifies the total volume that needs to be transferred, a maximum bandwidth that he/she can use, and a desired time period within which the transfer should be done. The algorithm can find alternate allocation possibilities, including earliest time for completion, or shortest transfer duration - leaving the choice to the user. We present a novel approach for path finding in …
Date: January 28, 2010
Creator: Balman, Mehmet; Chaniotakis, Evangelos; Shoshani, Arie & Sim, Alex
Object Type: Report
System: The UNT Digital Library
Simulating Scintillator Light Collection Using Measured Optical Reflectance (open access)

Simulating Scintillator Light Collection Using Measured Optical Reflectance

To accurately predict the light collection from a scintillating crystal through Monte Carlo simulations, it is crucial to know the angular distribution from the surface reflectance. Current Monte Carlo codes allow the user to set the optical reflectance to a linear combination of backscatter spike, specular spike, specular lobe, and Lambertian reflections. However, not all light distributions can be expressed in this way. In addition, the user seldom has the detailed knowledge about the surfaces that is required for accurate modeling. We have previously measured the angular distributions within BGO crystals and now incorporate these data as look-up-tables (LUTs) into modified Geant4 and GATE Monte Carlo codes. The modified codes allow the user to specify the surface treatment (ground, etched, or polished), the attached reflector (Lumirror(R), Teflon(R), ESR film, Tyvek(R), or TiO paint), and the bonding type (air-coupled or glued). Each LUT consists of measured angular distributions with 4o by 5o resolution in theta and phi, respectively, for incidence angles from 0? to 90? degrees, in 1o-steps. We compared the new codes to the original codes by running simulations with a 3 x 10 x 30 mm3 BGO crystal coupled to a PMT. The simulations were then compared to measurements. …
Date: January 28, 2010
Creator: Janecek, Martin & Moses, William
Object Type: Article
System: The UNT Digital Library
The TAOS Project Stellar Variability II. Detection of 15 Variable Stars (open access)

The TAOS Project Stellar Variability II. Detection of 15 Variable Stars

The Taiwanese-American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data - covering timescales from a fraction of a second to a few hundred days - are a useful source to study stellar variability. A total of 167 star fields, mostly along the ecliptic plane, have been selected for photometric monitoring with the TAOS telescopes. This paper presents our initial analysis of a search for periodic variable stars from the time-series TAOS data on one particular TAOS field, No. 151 (RA = 17{sup h} 30{sup m} 6.67{sup s}, Dec = 27 degrees, 17 minutes, 30 seconds, J2000), which had been observed over 47 epochs in 2005. A total of 81 candidate variables are identified in the 3 square degree field, with magnitudes in the range 8 < R < 16. On the basis of the periodicity and shape of the lightcurves, 32 variables, 18 of which were previously unknown, are classified as RR Lyrae, Cepheid, {delta} Scuti, SX Phonencis, semi-regular and eclipsing binaries.
Date: January 28, 2010
Creator: Mondal, S.; Lin, C. C.; Zhang, Z. W.; Alcock, C.; Axelrod, T.; Bianco, F. B. et al.
Object Type: Article
System: The UNT Digital Library
Algorithm Summary and Evaluation: Automatic Implementation of Ringdown Analysis for Electromechanical Mode Identification from Phasor Measurements (open access)

Algorithm Summary and Evaluation: Automatic Implementation of Ringdown Analysis for Electromechanical Mode Identification from Phasor Measurements

Small signal stability problems are one of the major threats to grid stability and reliability. Prony analysis has been successfully applied on ringdown data to monitor electromechanical modes of a power system using phasor measurement unit (PMU) data. To facilitate an on-line application of mode estimation, this paper develops a recursive algorithm for implementing Prony analysis and proposed an oscillation detection method to detect ringdown data in real time. By automatically detecting ringdown data, the proposed method helps guarantee that Prony analysis is applied properly and timely on the ringdown data. Thus, the mode estimation results can be performed reliably and timely. The proposed method is tested using Monte Carlo simulations based on a 17-machine model and is shown to be able to properly identify the oscillation data for on-line application of Prony analysis. In addition, the proposed method is applied to field measurement data from WECC to show the performance of the proposed algorithm.
Date: February 28, 2010
Creator: Zhou, Ning; Huang, Zhenyu; Tuffner, Francis K.; Jin, Shuangshuang; Lin, Jenglung & Hauer, Matthew L.
Object Type: Report
System: The UNT Digital Library
ARM Climate Research Facility Instrumentation Status and Information January 2010 (open access)

ARM Climate Research Facility Instrumentation Status and Information January 2010

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: February 28, 2010
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Efficient Windows Collaborative: Research Tool Dissemination to Increase Energy Efficient Fenestration Product Penetration (open access)

Efficient Windows Collaborative: Research Tool Dissemination to Increase Energy Efficient Fenestration Product Penetration

The project goals covered both the residential and commercial windows markets and involved a range of audiences such as window manufacturers, builders, homeowners, design professionals, utilities, and public agencies. Essential goals included: (1) Creation of 'Master Toolkits' of information that integrate diverse tools, rating systems, and incentive programs, customized for key audiences such as window manufacturers, design professionals, and utility programs. (2) Delivery of education and outreach programs to multiple audiences through conference presentations, publication of articles for builders and other industry professionals, and targeted dissemination of efficient window curricula to professionals and students. (3) Design and implementation of mechanisms to encourage and track sales of more efficient products through the existing Window Products Database as an incentive for manufacturers to improve products and participate in programs such as NFRC and ENERGY STAR. (4) Development of utility incentive programs to promote more efficient residential and commercial windows. Partnership with regional and local entities on the development of programs and customized information to move the market toward the highest performing products. An overarching project goal was to ensure that different audiences adopt and use the developed information, design and promotion tools and thus increase the market penetration of energy efficient fenestration …
Date: February 28, 2010
Creator: Alliance to Save Energy (U.S.)
Object Type: Report
System: The UNT Digital Library
Hanford Site Annual Report Radiological Dose Calculation Upgrade Evaluation (open access)

Hanford Site Annual Report Radiological Dose Calculation Upgrade Evaluation

Operations at the Hanford Site, Richland, Washington, result in the release of radioactive materials to offsite residents. Site authorities are required to estimate the dose to the maximally exposed offsite resident. Due to the very low levels of exposure at the residence, computer models, rather than environmental samples, are used to estimate exposure, intake, and dose. A DOS-based model has been used in the past (GENII version 1.485). GENII v1.485 has been updated to a Windows®-based software (GENII version 2.08). Use of the updated software will facilitate future dose evaluations, but must be demonstrated to provide results comparable to those of GENII v1.485. This report describes the GENII v1.485 and GENII v2.08 dose exposure, intake, and dose estimates for the maximally exposed offsite resident reported for calendar year 2008. The GENII v2.08 results reflect updates to implemented algorithms. No two environmental models produce the same results, as was again demonstrated in this report. The aggregated dose results from 2008 Hanford Site airborne and surface water exposure scenarios provide comparable dose results. Therefore, the GENII v2.08 software is recommended for future offsite resident dose evaluations.
Date: February 28, 2010
Creator: Snyder, Sandra F.
Object Type: Report
System: The UNT Digital Library
Integrated Control of Next Generation Power System (open access)

Integrated Control of Next Generation Power System

Control methodologies provide the necessary data acquisition, analysis and corrective actions needed to maintain the state of an electric power system within acceptable operating limits. These methods are primarily software-based algorithms that are nonfunctional unless properly integrated with system data and the appropriate control devices. Components of the control of power systems today include protective relays, supervisory control and data acquisition (SCADA), distribution automation (DA), feeder automation, software agents, sensors, control devices and communications. Necessary corrective actions are still accomplished using large electromechanical devices such as vacuum, oil and gas-insulated breakers, capacitor banks, regulators, transformer tap changers, reclosers, generators, and more recently FACTS (flexible AC transmission system) devices. The recent evolution of multi-agent system (MAS) technologies has been reviewed and effort made to integrate MAS into next generation power systems. A MAS can be defined as “…a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilities…”. These problem solvers, often called agents, are autonomous and may be heterogeneous in nature. This project has shown that a MAS has significant advantages over a single, monolithic, centralized problem solver for next generation power systems. Various communication media are being used in the electric power …
Date: February 28, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Singapore's Zero-Energy Building's daylight monitoring system (open access)

Singapore's Zero-Energy Building's daylight monitoring system

A setup to monitor the daylighting performance of different glazing types in Singapore is presented. The glazing is installed in the facade of four dedicated testing chambers in BCAA's Zero Energy Building in Singapore. These test rooms are equipped with sensors that both record illuminances on the work plane, and luminances as seen by occupants. The physical and logical design of the monitoring system is presented. Criteria to assess the daylighting performance are introduced, and initial results of the work in progress are presented.
Date: February 28, 2010
Creator: Grobe, Lars; Wittkopf, Stephen; Pandey, Anupama Rana; Xiaoming, Yang; Seng, Ang Kian; Scartezzini, Jean-Louis et al.
Object Type: Article
System: The UNT Digital Library
Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage (open access)

Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage

This program was devoted to significantly extending the limits of hydrogen storage technology for practical transportation applications. To meet the hydrogen capacity goals set forth by the DOE, solid-state materials consisting of light elements were developed. Many light element compounds are known that have high capacities. However, most of these materials are thermodynamically too stable, and they release and store hydrogen much too slowly for practical use. In this project we developed new light element chemical systems that have high hydrogen capacities while also having suitable thermodynamic properties. In addition, we developed methods for increasing the rates of hydrogen exchange in these new materials. The program has significantly advanced (1) the application of combined hydride systems for tuning thermodynamic properties and (2) the use of nanoengineering for improving hydrogen exchange. For example, we found that our strategy for thermodynamic tuning allows both entropy and enthalpy to be favorably adjusted. In addition, we demonstrated that using porous supports as scaffolds to confine hydride materials to nanoscale dimensions could improve rates of hydrogen exchange by > 50x. Although a hydrogen storage material meeting the requirements for commercial development was not achieved, this program has provided foundation and direction for future efforts. More …
Date: February 28, 2010
Creator: Liu, Ping & Vajo, John J.
Object Type: Report
System: The UNT Digital Library
Time-windows-based filtering method for near-surface detection of leakage from geologic carbon sequestration sites (open access)

Time-windows-based filtering method for near-surface detection of leakage from geologic carbon sequestration sites

We use process-based modeling techniques to characterize the temporal features of natural biologically controlled surface CO{sub 2} fluxes and the relationships between the assimilation and respiration fluxes. Based on these analyses, we develop a signal-enhancing technique that combines a novel time-window splitting scheme, a simple median filtering, and an appropriate scaling method to detect potential signals of leakage of CO{sub 2} from geologic carbon sequestration sites from within datasets of net near-surface CO{sub 2} flux measurements. The technique can be directly applied to measured data and does not require subjective gap filling or data-smoothing preprocessing. Preliminary application of the new method to flux measurements from a CO{sub 2} shallow-release experiment appears promising for detecting a leakage signal relative to background variability. The leakage index of ?2 was found to span the range of biological variability for various ecosystems as determined by observing CO{sub 2} flux data at various control sites for a number of years.
Date: February 28, 2010
Creator: Pan, L.; Lewicki, J. L.; Oldenburg, C. M. & Fischer, M. L.
Object Type: Article
System: The UNT Digital Library
Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan (open access)

Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan

During the period 1980 to 2002, China experienced a 5% average annual reduction in energy consumption per unit of gross domestic product (GDP). The period 2002-2005 saw a dramatic reversal of the historic relationship between energy use and GDP growth: energy use per unit of GDP increased an average of 3.8% per year during this period (NBS, various years). China's 11th Five Year Plan (FYP), which covers the period 2006-2010, required all government divisions at different levels to reduce energy intensity by 20% in five years in order to regain the relationship between energy and GDP growth experienced during the 1980s and 1990s. This report provides an assessment of selected policies and programs that China has instituted in its quest to fulfill the national goal of a 20% reduction in energy intensity by 2010. The report finds that China has made substantial progress toward its goal of achieving 20% energy intensity reduction from 2006 to 2010 and that many of the energy-efficiency programs implemented during the 11th FYP in support of China's 20% energy/GDP reduction goal appear to be on track to meet - or in some cases even exceed - their energy-saving targets. It appears that most of the …
Date: April 28, 2010
Creator: Levine, Mark D.; Price, Lynn; Zhou, Nan; Fridley, David; Aden, Nathaniel; Lu, Hongyou et al.
Object Type: Report
System: The UNT Digital Library
Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler (open access)

Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________
Date: April 28, 2010
Creator: Qin, Hong; Davidson, Ronald C. & Logan, B. Grant
Object Type: Report
System: The UNT Digital Library
Measurement of the gamma gamma* to eta_c transition form factor (open access)

Measurement of the gamma gamma* to eta_c transition form factor

The authors study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sub c}, {eta}{sub c} {yields} K{sub S}K{sup {+-}}{pi}{sup {-+}} and obtain {eta}{sub c} mass and width values 2982.2 {+-} 0.4 {+-} 1.6 MeV/c{sup 2} and 31.7 {+-} 1.2 {+-} 0.8 MeV, respectively. They find {Lambda}({eta}{sub c} {yields} {gamma}{gamma}){Beta}({eta}{sub c} {yields} K{bar K}{pi}) = 0.374 {+-} 0.009 {+-} 0.031 keV, and measure the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor in the momentum transfer range from 2 to 50 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Date: April 28, 2010
Creator: Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E. et al.
Object Type: Article
System: The UNT Digital Library
Non-diffusive spin dynamics in a two-dimensional electron gas (open access)

Non-diffusive spin dynamics in a two-dimensional electron gas

We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wavevector range from zero to 6 x 10{sup 4} cm{sup -1}. We find that the spin polarization lifetime is maximal at nonzero wavevector, in contrast with expectation based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit coupling.
Date: April 28, 2010
Creator: Weber, C.P.
Object Type: Article
System: The UNT Digital Library
Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons (open access)

Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic …
Date: April 28, 2010
Creator: Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P. et al.
Object Type: Report
System: The UNT Digital Library
Phytoremediation of ionic and methylmercury pollution (open access)

Phytoremediation of ionic and methylmercury pollution

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.
Date: April 28, 2010
Creator: Meagher, Richard B
Object Type: Report
System: The UNT Digital Library
Quantum Detection and Invisibility in Coherent Nanostructures (open access)

Quantum Detection and Invisibility in Coherent Nanostructures

We address quantum invisibility in the context of electronics in nanoscale quantum structures. In analogy with metamaterials, we use the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with respect to inelastic electron scattering spectroscopy in combination with scanning tunneling microscopy, and we propose a design strategy. A simple illustration of the invisibility is given in terms of an elliptic quantum corral containing a molecule, with a local vibrational mode, at one of the foci. Our work has implications to quantum information technology and presents new tools for nonlocal quantum detection and distinguishing between different molecules.
Date: April 28, 2010
Creator: Fransson, J.
Object Type: Article
System: The UNT Digital Library
Quantum Phase Extraction in Isospectral Electronic Nanostructures (open access)

Quantum Phase Extraction in Isospectral Electronic Nanostructures

Quantum phase is not a direct observable and is usually determined by interferometric methods. We present a method to map complete electron wave functions, including internal quantum phase information, from measured single-state probability densities. We harness the mathematical discovery of drum-like manifolds bearing different shapes but identical resonances, and construct quantum isospectral nanostructures possessing matching electronic structure but divergent physical structure. Quantum measurement (scanning tunneling microscopy) of these 'quantum drums' [degenerate two-dimensional electron states on the Cu(111) surface confined by individually positioned CO molecules] reveals that isospectrality provides an extra topological degree of freedom enabling robust quantum state transplantation and phase extraction.
Date: April 28, 2010
Creator: Moon, Christopher
Object Type: Article
System: The UNT Digital Library