Enhanced Attenuation Technologies: Passive Soil Vapor Extraction (open access)

Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface …
Date: March 15, 2010
Creator: Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D. & Newell, C.
Object Type: Report
System: The UNT Digital Library
Enhanced superconducting pairing interaction in indium-doped tin telluride (open access)

Enhanced superconducting pairing interaction in indium-doped tin telluride

The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x < x{sub c}. By examining the effect of In dopant atoms on both T{sub c} and the temperature of the ferroelectric structural phase transition, T{sub SPT}, we show that phonon modes related to this transition are not responsible for this T{sub c} enhancement, and discuss a plausible candidate based on the unique properties of the indium impurities.
Date: February 15, 2010
Creator: Erickson, A.S.; Chu, J.-H.; /Stanford U., Appl. Phys. Dept. /Stanford U., Geballe Lab.; Toney, M.F.; Geballe, T.H.; Fisher, I.R. et al.
Object Type: Article
System: The UNT Digital Library
Enrichment, isolation and characterization of fungi tolerant to 1-ethyl-3-methylimidazolium acetate (open access)

Enrichment, isolation and characterization of fungi tolerant to 1-ethyl-3-methylimidazolium acetate

This work aims to characterize microbial tolerance to 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), ionic liquid that has emerged as a novel biomass pretreatment for lignocellulosic biomass. Enrichment experiments performed using inocula treated with [C2mim][OAc] under solid and liquid cultivation yielded fungal populationsdominated by Aspergilli. Ionic liquid-tolerant Aspergillus isolates from these enrichments were capable of growing in a radial plate growth assay in the presence of 10% [C2mim][OAc]. When a [C2mim][OAc]-tolerant Aspergillus fumigatus strain was grown in the presence of switchgrass, endoglucanases and xylanases were secreted that retained residual enzymatic activity in the presence of 20% [C2mim][OAc]. The results of the study suggest tolerance to ionic liquids is a general property of Aspergilli. Tolerance to an industrially important ionic liquid was discovered in a fungal genera that is widely used in biotechnology, including biomass deconstruction.
Date: December 15, 2010
Creator: Singer, S.W.; Reddy, A. P.; Gladden, J. M.; Guo, H.; Hazen, T.C.; Simmons, B. A. et al.
Object Type: Article
System: The UNT Digital Library
Establishment of an NWP testbed using ARM data (open access)

Establishment of an NWP testbed using ARM data

The aim of the FAst-physics System TEstbed and Research (FASTER) project is to evaluate and improve the parameterizations of fast physics (involving clouds, precipitation, aerosol) in numerical models using ARM measurements. One objective within FASTER is to evaluate model representations of fast physics with long-term continuous cloud observations by use of an 'NWP testbed'. This approach was successful in the European Cloudnet project. NWP model data (NCEP, ECMWF, etc.) is routinely output at ARM sites, and model evaluation can potentially be achieved in quasi-real time. In this poster, we will outline our progress in the development of the NWP testbed and discuss the successful integration of ARM algorithms, such as ARSCL, with algorithms and lessons learned from Cloudnet. Preliminary results will be presented of the evaluation of the ECMWF, NCEP, and UK Met Office models over the SGP site using this approach.
Date: March 15, 2010
Creator: O'Connor, E.; Liu, Y. & Hogan, R.
Object Type: Article
System: The UNT Digital Library
Evaluation of Alumina-Forming Austenitic Stainless Steel Alloys in Microturbines (open access)

Evaluation of Alumina-Forming Austenitic Stainless Steel Alloys in Microturbines

Oak Ridge National Laboratory (ORNL) and Capstone Turbine Corporation (CTC) participated in an in-kind cost share cooperative research and development agreement (CRADA) effort under the auspices of the Energy Efficiency and Renewable Energy (EERE) Technology Maturation Program to explore the feasibility for use of developmental ORNL alumina-forming austenitic (AFA) stainless steels as a material of construction for microturbine recuperator components. ORNL delivered test coupons of three different AFA compositions to CTC. The coupons were exposed in steady-state elevated turbine exit temperature (TET) engine testing, with coupons removed for analysis after accumulating ~1,500, 3,000, 4,500, and 6,000 hours of operation. Companion test coupons were also exposed in oxidation testing at ORNL at 700-800°C in air with 10% H2O. Post test assessment of the coupons was performed at ORNL by light microscopy and electron probe microanalysis. The higher Al and Nb containing AFA alloys exhibited excellent resistance to oxidation/corrosion, and thus show good promise for recuperator applications.
Date: September 15, 2010
Creator: Brady, M.P. & Matthews, W.J. (Capstone Turbine Corp.)
Object Type: Report
System: The UNT Digital Library
Evaluation of Glass Density to Support the Estimation of Fissile Mass Loadings from Iron Concentrations in SB6 Glasses (open access)

Evaluation of Glass Density to Support the Estimation of Fissile Mass Loadings from Iron Concentrations in SB6 Glasses

The Department of Energy - Savannah River (DOE-SR) previously provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of the guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft{reg_sign} Excel{reg_sign} spreadsheet for the evaluation of fissile loading in Sludge Batch 5 glass based on the Fe concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that SRNL provide the necessary information to allow SRR to update the Excel spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 6 (SB6). One of the primary inputs into the fissile loading spreadsheet includes a bounding density for SB6-based glasses. Based on the measured density data of select SB6 variability study glasses, SRNL recommends that SRR utilize the 99/99 Upper Tolerance Limit (UTL) density value at 38% WL (2.823 g/cm{sup 3}) as a bounding density for SB6 glasses to assess the fissile concentration in this glass system. That is, the 2.823 g/cm{sup 3} is recommended as a key (and fixed) input into the …
Date: December 15, 2010
Creator: Edwards, T. & Peeler, D.
Object Type: Report
System: The UNT Digital Library
Event-by-Event Study of Prompt Neutrons from 239Pu (open access)

Event-by-Event Study of Prompt Neutrons from 239Pu

Employing a recently developed Monte Carlo model, we study the fission of {sup 240}Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1 MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies of less than 2 MeV.
Date: January 15, 2010
Creator: Vogt, R; Randrup, J; Pruet, J & Younes, W
Object Type: Article
System: The UNT Digital Library
Evidence for coupling between collective state and phonons in two-dimensional charge-density-wave systems (open access)

Evidence for coupling between collective state and phonons in two-dimensional charge-density-wave systems

We report on a Raman scattering investigation of the charge-density-wave (CDW), quasi two-dimensional rare-earth tri-tellurides RTe{sub 3} (R = La, Ce, Pr, Nd, Sm, Gd and Dy) at ambient pressure, and of LaTe{sub 3} and CeTe{sub 3} under externally applied pressure. The observed phonon peaks can be ascribed to the Raman active modes for both the undistorted as well as the distorted lattice in the CDW state by means of a first principles calculation. The latter also predicts the Kohn anomaly in the phonon dispersion, driving the CDW transition. The integrated intensity of the two most prominent modes scales as a characteristic power of the CDW-gap amplitude upon compressing the lattice, which provides clear evidence for the tight coupling between the CDW condensate and the vibrational modes.
Date: February 15, 2010
Creator: Lavagnini, M.; Baldini, M.; Sacchetti, A.; Castro, D. Di; Delley, B.; Monnier, R. et al.
Object Type: Article
System: The UNT Digital Library
Exact expressions and accurate approximations for the dependences of radius and index of refraction of solutions of inorganic solutes on relative humidity (open access)

Exact expressions and accurate approximations for the dependences of radius and index of refraction of solutions of inorganic solutes on relative humidity

Light scattering by aerosols plays an important role in Earth’s radiative balance, and quantification of this phenomenon is important in understanding and accounting for anthropogenic influences on Earth’s climate. Light scattering by an aerosol particle is determined by its radius and index of refraction, and for aerosol particles that are hygroscopic, both of these quantities vary with relative humidity RH. Here exact expressions are derived for the dependences of the radius ratio (relative to the volume-equivalent dry radius) and index of refraction on RH for aqueous solutions of single solutes. Both of these quantities depend on the apparent molal volume of the solute in solution and on the practical osmotic coefficient of the solution, which in turn depend on concentration and thus implicitly on RH. Simple but accurate approximations are also presented for the RH dependences of both radius ratio and index of refraction for several atmospherically important inorganic solutes over the entire range of RH values for which these substances can exist as solution drops. For all substances considered, the radius ratio is accurate to within a few percent, and the index of refraction to within ~0.02, over this range of RH. Such parameterizations will be useful in radiation …
Date: March 15, 2010
Creator: Lewis, E. R. & Schwartz, S.
Object Type: Article
System: The UNT Digital Library
Exascale for Energy: The Role of Exascale Computing in Energy Security (open access)

Exascale for Energy: The Role of Exascale Computing in Energy Security

How will the United States satisfy energy demand in a tightening global energy marketplace while, at the same time, reducing greenhouse gas emissions? Exascale computing -- expected to be available within the next eight to ten years ? may play a crucial role in answering that question by enabling a paradigm shift from test-based to science-based design and engineering. Computational modeling of complete power generation systems and engines, based on scientific first principles, will accelerate the improvement of existing energy technologies and the development of new transformational technologies by pre-selecting the designs most likely to be successful for experimental validation, rather than relying on trial and error. The predictive understanding of complex engineered systems made possible by computational modeling will also reduce the construction and operations costs, optimize performance, and improve safety. Exascale computing will make possible fundamentally new approaches to quantifying the uncertainty of safety and performance engineering. This report discusses potential contributions of exa-scale modeling in four areas of energy production and distribution: nuclear power, combustion, the electrical grid, and renewable sources of energy, which include hydrogen fuel, bioenergy conversion, photovoltaic solar energy, and wind turbines. Examples of current research are taken from projects funded by the U.S. …
Date: July 15, 2010
Creator: Authors, Various
Object Type: Report
System: The UNT Digital Library
Experimental Studies on Grooved Surfaces to Suppress Secondary Electron Emission (open access)

Experimental Studies on Grooved Surfaces to Suppress Secondary Electron Emission

Grooved surfaces are effective to suppress the secondary electron emission, and can be a promising technique to mitigate the electron cloud effect in positron/proton storage rings. Aiming for the application in a dipole-type magnetic field, various shapes of triangular grooved surfaces have been studied at KEK. The grooves tested here have vertex angles of 20-30{sup o}, depths of 2.5-5.0 mm, and vertex roundness of 0.05-0.2 mm. In a laboratory, the secondary electron yields (SEY) of small test pieces were measured using an electron beam in a magnetic-free condition. The grooved surfaces clearly had low SEY compared to flat surfaces of the same materials. The grooves with sharper vertexes had smaller SEY. A test chamber installed in a wiggler magnet of the KEKB positron ring was used to investigate the efficacy of the grooved surface in a strong magnetic field. In the chamber, a remarkable reduction in the electron density around the beam orbit was observed compared to the case of a flat surface with TiN coating.
Date: June 15, 2010
Creator: Suetsugu, Y.; Fukuma, H.; Shibata, K.; Pivi, M. & Wang, L.
Object Type: Article
System: The UNT Digital Library
Extending ALE3D, an Arbitrarily Connected hexahedral 3D Code, to Very Large Problem Size (U) (open access)

Extending ALE3D, an Arbitrarily Connected hexahedral 3D Code, to Very Large Problem Size (U)

As the number of compute units increases on the ASC computers, the prospect of running previously unimaginably large problems is becoming a reality. In an arbitrarily connected 3D finite element code, like ALE3D, one must provide a unique identification number for every node, element, face, and edge. This is required for a number of reasons, including defining the global connectivity array required for domain decomposition, identifying appropriate communication patterns after domain decomposition, and determining the appropriate load locations for implicit solvers, for example. In most codes, the unique identification number is defined as a 32-bit integer. Thus the maximum value available is 231, or roughly 2.1 billion. For a 3D geometry consisting of arbitrarily connected hexahedral elements, there are approximately 3 faces for every element, and 3 edges for every node. Since the nodes and faces need id numbers, using 32-bit integers puts a hard limit on the number of elements in a problem at roughly 700 million. The first solution to this problem would be to replace 32-bit signed integers with 32-bit unsigned integers. This would increase the maximum size of a problem by a factor of 2. This provides some head room, but almost certainly not one that …
Date: December 15, 2010
Creator: Nichols, A. L.
Object Type: Article
System: The UNT Digital Library
Extending the frontiers of mass spectrometric instrumentation and methods (open access)

Extending the frontiers of mass spectrometric instrumentation and methods

The focus of this dissertation is two-fold: developing novel analysis methods using mass spectrometry and the implementation and characterization of a novel ion mobility mass spectrometry instrumentation. The novel mass spectrometry combines ion trap for ion/ion reactions coupled to an ion mobility cell. The long term goal of this instrumentation is to use ion/ion reactions to probe the structure of gas phase biomolecule ions. The three ion source - ion trap - ion mobility - qTOF mass spectrometer (IT - IM - TOF MS) instrument is described. The analysis of the degradation products in coal (Chapter 2) and the imaging plant metabolites (Appendix III) fall under the methods development category. These projects use existing commercial instrumentation (JEOL AccuTOF MS and Thermo Finnigan LCQ IT, respectively) for the mass analysis of the degraded coal products and the plant metabolites, respectively. The coal degradation paper discusses the use of the DART ion source for fast and easy sample analysis. The sample preparation consisted of a simple 50 fold dilution of the soluble coal products in water and placing the liquid in front of the heated gas stream. This is the first time the DART ion source has been used for analysis of …
Date: December 15, 2010
Creator: Schieffer, Gregg
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Fast Ferroelectric L-Band Tuner for ILC Cavities (open access)

Fast Ferroelectric L-Band Tuner for ILC Cavities

Design, analysis, and low-power tests are described on a 1.3 GHz ferroelectric tuner that could find application in the International Linear Collider or in Project X at Fermi National Accelerator Laboratory. The tuner configuration utilizes a three-deck sandwich imbedded in a WR-650 waveguide, in which ferroelectric bars are clamped between conducting plates that allow the tuning bias voltage to be applied. Use of a reduced one-third structure allowed tests of critical parameters of the configuration, including phase shift, loss, and switching speed. Issues that were revealed that require improvement include reducing loss tangent in the ferroelectric material, development of a reliable means of brazing ferroelectric elements to copper parts of the tuner, and simplification of the mechanical design of the configuration.
Date: March 15, 2010
Creator: Hirshfield, Jay L
Object Type: Report
System: The UNT Digital Library
Fast Physics Testbed for the FASTER Project (open access)

Fast Physics Testbed for the FASTER Project

This poster describes the Fast Physics Testbed for the new FAst-physics System Testbed and Research (FASTER) project. The overall objective is to provide a convenient and comprehensive platform for fast turn-around model evaluation against ARM observations and to facilitate development of parameterizations for cloud-related fast processes represented in global climate models. The testbed features three major components: a single column model (SCM) testbed, an NWP-Testbed, and high-resolution modeling (HRM). The web-based SCM-Testbed features multiple SCMs from major climate modeling centers and aims to maximize the potential of SCM approach to enhance and accelerate the evaluation and improvement of fast physics parameterizations through continuous evaluation of existing and evolving models against historical as well as new/improved ARM and other complementary measurements. The NWP-Testbed aims to capitalize on the large pool of operational numerical weather prediction products. Continuous evaluations of NWP forecasts against observations at ARM sites are carried out to systematically identify the biases and skills of physical parameterizations under all weather conditions. The highresolution modeling (HRM) activities aim to simulate the fast processes at high resolution to aid in the understanding of the fast processes and their parameterizations. A four-tier HRM framework is established to augment the SCM- and NWP-Testbeds …
Date: March 15, 2010
Creator: Lin, W.; Liu, Y.; Hogan, R.; Neggers, R.; Jensen, M.; Fridlind, A. et al.
Object Type: Article
System: The UNT Digital Library
FASTER: A new DOE effort to bridge ESM and ASR sciences (open access)

FASTER: A new DOE effort to bridge ESM and ASR sciences

In order to better use the long-term ARM measurements to evaluate parameterizations of fast processes used in global climate models --- mainly those related to clouds, precipitation and aerosols, the DOE Earth System Modeling (ESM) program funds a new multi-institution project led by the Brookhaven National Laboratory, FAst -physics System Testbed and Research (FASTER). This poster will present an overview of this new project and its scientific relationships to the ASR sciences and ARM measurements.
Date: March 15, 2010
Creator: Liu, Y.
Object Type: Article
System: The UNT Digital Library
Features, Events and Processes for the Used Fuel Disposition Campaign (open access)

Features, Events and Processes for the Used Fuel Disposition Campaign

The Used Fuel Disposition (UFD) Campaign within DOE-NE is evaluating storage and disposal options for a range of waste forms and a range of geologic environments. To assess the potential performance of conceptual repository designs for the combinations of waste form and geologic environment, a master set of Features, Events, and Processes (FEPs) has been developed and evaluated. These FEPs are based on prior lists developed by the Yucca Mountain Project (YMP) and the international repository community. The objective of the UFD FEPs activity is to identify and categorize FEPs that are important to disposal system performance for a variety of disposal alternatives (i.e., combinations of waste forms, disposal concepts, and geologic environments). FEP analysis provides guidance for the identification of (1) important considerations in disposal system design, and (2) gaps in the technical bases. The UFD FEPs also support the development of performance assessment (PA) models to evaluate the long-term performance of waste forms in the engineered and geologic environments of candidate disposal system alternatives. For the UFD FEP development, five waste form groups and seven geologic settings are being considered. A total of 208 FEPs have been identified, categorized by the physical components of the waste disposal system …
Date: December 15, 2010
Creator: Blink, J. A.; Greenberg, H. R.; Caporuscio, F. A.; Houseworth, J. E.; Freeze, G. A.; Mariner, P. et al.
Object Type: Article
System: The UNT Digital Library
Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3 (open access)

Fermi Surface Evolution Across Multiple Charge Density Wave Transitions in ErTe3

The Fermi surface (FS) of ErTe{sub 3} is investigated using angle-resolved photoemission spectroscopy (ARPES). Low temperature measurements reveal two incommensurate charge density wave (CDW) gaps created by perpendicular FS nesting vectors. A large {Delta}{sub 1} = 175 meV gap arising from a CDW with c* - q{sub CDW1} {approx} 0.70(0)c* is in good agreement with the expected value. A second, smaller {Delta}{sub 2} = 50 meV gap is due to a second CDW with a* - q{sub CDW2} {approx} 0.68(5)a*. The temperature dependence of the FS, the two gaps and possible interaction between the CDWs are examined.
Date: February 15, 2010
Creator: Moore, R. G.; /SLAC, SSRL /Stanford U., Geballe Lab.; Brouet, V.; /Orsay, LPS; He, R.; /SLAC, SSRL /Stanford U., Geballe Lab. et al.
Object Type: Article
System: The UNT Digital Library
Ferromagnetism in the Mott insulator Ba2NaOsO6 (open access)

Ferromagnetism in the Mott insulator Ba2NaOsO6

Results are presented of single crystal structural, thermodynamic, and reflectivity measurements of the double-perovskite Ba{sub 2}NaOsO{sub 6}. These characterize the material as a 5d1 ferromagnetic Mott insulator with an ordered moment of {approx} 0.2 {micro}B per formula unit and T{sub C} = 6.8(3) K. The magnetic entropy associated with this phase transition is close to Rln2, indicating that the quartet groundstate anticipated from consideration of the crystal structure is split, consistent with a scenario in which the ferromagnetism is associated with orbital ordering.
Date: January 15, 2010
Creator: Erickson, A. S.; Misra, S.; Miller, G. J.; Harrison, W. A.; Kim, J. M. & Fisher, I. R.
Object Type: Article
System: The UNT Digital Library
Field-induced Gap and Quantized Charge Pumping in Nano-helix (open access)

Field-induced Gap and Quantized Charge Pumping in Nano-helix

We propose several novel physical phenomena based on nano-scale helical wires. Applying a static electric field transverse to the helical wire induces a metal to insulator transition, with the band gap determined by the applied voltage. Similar idea can be applied to 'geometrically' constructing one-dimensional systems with arbitrary external potential. With a quadrupolar electrode configuration, the electric field could rotate in the transverse plane, leading to a quantized dc charge current proportional to the frequency of the rotation. Such a device could be used as a new standard for the high precession measurement of the electric current. The inverse effect implies that passing an electric current through a helical wire in the presence of a transverse static electric field can lead to a mechanical rotation of the helix. This effect can be used to construct nano-scale electro-mechanical motors. Finally, our methodology also enables new ways of controlling and measuring the electronic properties of helical biological molecules such as the DNA.
Date: February 15, 2010
Creator: Qi, Xiao-Liang; /Stanford U., Phys. Dept. /Tsinghua U., Beijing; Zhang, Shou-Cheng & /Stanford U., Phys. Dept.
Object Type: Report
System: The UNT Digital Library
Final Report for DOE Project Number: DE-FG02-05ER46241 (open access)

Final Report for DOE Project Number: DE-FG02-05ER46241

Hydrogen storage is the most challenging task for the hydrogen economy. We established a multidisciplinary research program for high throughput combinatorial synthesis and characterization of novel nanoporous and metastable complex hydrides, coupled to fundamental material studies including electronic, structural and kinetic transport modeling, and pump-probe experiments. Our research is based the concept of hybrid nanostructures that store hydrogen by a combination of chemi- and physorption: atomic hydrogen is stored in metastable hydrides while molecule hydrogen is stored in the nanometer pores of the hydrides. Metastable nanostructured hydride has been achieved by introducing structural and compositional disorders through high throughput elemental substitution/doping, catalyst addition, and nonequilibrium processing. Fast screening compatible with the combinatorial synthesis was achieved by combining X-ray structural characterization with the development of a laser-based microbalance. Manufacturing of nanoporous metahydrides that are identified as promising by the combinatorial synthesis has been explored along with the materials search.
Date: March 15, 2010
Creator: Chen, Gang; Dresselhaus, Mildred S.; Grigoropoulos, Costas P.; Mao, Samuel S.; Xiang, Xiaodong & Zeng, Taofang
Object Type: Report
System: The UNT Digital Library
Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials (open access)

Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials

This final report details results, conclusions, and opportunities for future effort derived from the study. The work involved combining the molecular engineering of photoactive Ti-alkoxide systems and the optical excitation of hydrolysis and condensation reactions to influence the development of the metal-oxygen-metal network at the onset of material formation. Selective excitation of the heteroleptic alkoxides, coupled with control of alkoxide local chemical environment, enabled network connectivity to be influenced and formed the basis for direct deposition and patterning of Ti-oxide-based materials. The research provided new insights into the intrinsic photoresponse and assembly of these complex, alkoxide molecules. Using a suite of electronic, vibrational, and nuclear spectroscopic probes, coupled with quantum chemical computation, the excitation wavelength and fluence dependence of molecular photoresponse and the nature of subsequent hydrolysis and condensation processes were probed in pyridine-carbinol-based Ti-alkoxides with varied counter ligand groups. Several methods for the patterning of oxide material formation were demonstrated, including the integration of this photoprocessing approach with conventional, dip-coating methodologies.
Date: October 15, 2010
Creator: B.G. Potter, Jr.
Object Type: Report
System: The UNT Digital Library
Final Technical Report DOE/GO/13142-1 (open access)

Final Technical Report DOE/GO/13142-1

This research adds to the understanding of the areas of residual starch and biomass conversion to alcohol, by providing data from pilot plant equipment of larger scale than the minimum required to give commercially scalable data. Instrumentation and control is in place to capture the information produced, for economic and technical evaluation. The impact of rheology, recycle streams, and residence time distributions on the technical and economic performance can be assessed. Various processes can be compared technically and economically because the pilot plants are readily modifiable. Several technologies for residual starch yield improvement have been identified, implemented, and patent applications filed. Various biomass-to-ethanol processes have been compared and one selected for technical optimization and commercialization. The technical and economic feasibility of the current simplified biomass conversion process is being confirmed by intensive pilot plant efforts as of this writing. Optimization of the feedstock handling and pretreatment is occurring to increase the alcohol yield above the minimum commercially viable level already demonstrated. Samples of biomass residue and reactor blowdown condensate are being collected to determine the technical and economic performance of the high-water-recycle waste treatment system being considered for the process. The project is of benefit to the public because it …
Date: September 15, 2010
Creator: Mulvihill, Patrick & Nguyen, Quang
Object Type: Report
System: The UNT Digital Library
First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus (open access)

First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus

Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________
Date: July 15, 2010
Creator: Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Bell, R.; Gates, D.; Goldston, R. et al.
Object Type: Report
System: The UNT Digital Library