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Mississippi State Biodiesel Production Project
Biodiesel is a renewable fuel conventionally generated from vegetable oils and animal fats that conforms to ASTM D6751. Depending on the free fatty acid content of the feedstock, biodiesel is produced via transesterification, esterification, or a combination of these processes. Currently the cost of the feedstock accounts for more than 80% of biodiesel production cost. The main goal of this project was to evaluate and develop non-conventional feedstocks and novel processes for producing biodiesel. One of the most novel and promising feedstocks evaluated involves the use of readily available microorganisms as a lipid source. Municipal wastewater treatment facilities (MWWTF) in the USA produce (dry basis) of microbial sludge annually. This sludge is composed of a variety of organisms, which consume organic matter in wastewater. The content of phospholipids in these cells have been estimated at 24% to 25% of dry mass. Since phospholipids can be transesterified they could serve as a ready source of biodiesel. Examination of the various transesterification methods shows that in situ conversion of lipids to FAMEs provides the highest overall yield of biodiesel. If one assumes a 7.0% overall yield of FAMEs from dry sewage sludge on a weight basis, the cost per gallon of extracted …
Date:
March 20, 2008
Creator:
Hernandez, Rafael; French, Todd; Fernando, Sandun; Li, Tingyu; Braasch, Dwane; Silva, Juan et al.
Object Type:
Report
System:
The UNT Digital Library
Update of Time-Dependent CP Asymmetry Measurements in b to c-cbar-s Decays
We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 {+-} 5) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II B factory. The time-dependent CP asymmetry parameters measured from J/{psi}K{sub S}{sup 0}, J/{psi}K{sub L}{sup 0}, {psi}(2S)K{sub S}{sup 0}, {chi}{sub c1}K{sub S}{sup 0}, {eta}{sub c}K{sub S}{sup 0}, and J/{psi}K*{sup 0} decays are: (1) C{sub f} = 0.026 {+-} 0.020(stat) {+-} 0.016(syst); and (2) S{sub f} = 0.691 {+-} 0.029(stat) {+-} 0.014(syst).
Date:
August 20, 2008
Creator:
Aubert, B.
Object Type:
Article
System:
The UNT Digital Library
The structure of mixed H2O-OH monolayer films on Ru(0001)
Scanning tunneling microscopy (STM) and x-ray absorption spectroscopy (XAS) have been used to study the structures produced by water on Ru(0001) at temperatures above 140 K. It was found that while undissociated water layers are metastable below 140 K, heating above this temperature produces drastic transformations whereby a fraction of the water molecules partially dissociate and form mixed H{sub 2}O-OH structures. XPS and XAS revealed the presence of hydroxyl groups with their O-H bond essentially parallel to the surface. STM images show that the mixed H{sub 2}O-OH structures consist of long narrow stripes aligned with the three crystallographic directions perpendicular to the close-packed atomic rows of the Ru(0001) substrate. The internal structure of the stripes is a honeycomb network of H-bonded water and hydroxyl species. We found that the metastable low temperature molecular phase can also be converted to a mixed H{sub 2}O-OH phase through excitation by the tunneling electrons when their energy is 0.5 eV or higher above the Fermi level. Structural models based on the STM images were used for Density Functional Theory optimizations of the stripe geometry. The optimized geometry was then utilized to calculate STM images for comparison with the experiment.
Date:
October 20, 2008
Creator:
Tatarkhanov, M.; Fomin, E.; Salmeron, M.; Andersson, K.; Ogasawara, H.; Pettersson, L.G.M. et al.
Object Type:
Article
System:
The UNT Digital Library
Temperature response of 129Xe depolarization transfer and its application for ultra-sensitive NMR detection
Temporary trapping of atomic xenon in functionalized cryptophane cages makes the high sensitivity of hyperpolarized (hp) 129Xe available for highly specific NMR detection of biomolecules like proteins in solution. Here, we study the signal transfer onto a reservoir of unbound hp xenon by gating the residence time of the nuclei in the cage through the temperature-dependent exchange rate. Temperature changes were detectable immediately as an altered reservoir signal and yielded a sensitivity of 0.6 K. The temperature response is adjustable with lower concentrations of caged xenon providing more sensitivity at higher temperatures and allows ultra-sensitive detection of such molecular cages at 310 K. Functionalized cryptophane could be detected at concentrations as low as 10nM which corresponds to a 4000-fold sensitivity enhancement compared to conventional detection. This sensitivity makes hp-NMR capable of detecting such constructs in concentrations far belowthe detection limit by UV-visible light absorbance.
Date:
March 20, 2008
Creator:
Schroeder, Leif; Schroder, Leif; Meldrum, Tyler; Smith, Monica; Lowery, Thomas J.; Wemmer, David E. et al.
Object Type:
Article
System:
The UNT Digital Library
The Role of a Host Protein (TIP) in the Resistance Response of Arabidopsis to Turnip Crinkle Virus Infection.
Our research on Turnip crinkle virus (TCV) has shown that the viral capsid protein (CP) is both a virulence factor as well as the elicitor of a hypersensitive resistance response (HR) to the virus in Arabidopsis. Initially, we identified a protein from Arabidopsis that specifically interacted with the viral CP using a yeast two-hybrid screen. This protein, designated TIP for TCV-Interacting Protein, is a member of the NAC family of plant transcription factors implicated in the regulation of development and senescence. When TCV CP was mutated to eliminate its ability to interact with TIP, the corresponding virus mutants broke the HR-mediated resistance conferred by the HRT resistance (R) gene in Arabidopsis ecotype Dijon (Di)-17. This result suggested that TIP is a component of the signal transduction pathway that leads to the genetically specified TCV resistance. We next confirmed that TIP and the viral CP interact in plant cells and that this interaction prevents nuclear localization of this transcription factor. We demonstrated that TCV CP suppresses post-transcriptional gene silencing (PTGS), a newly discovered RNA-mediated defense system in plants. Together these results suggest that the CP is a virulence factor that could well be functioning through its interaction with TIP. We have …
Date:
October 20, 2008
Creator:
Morris, T. Jack
Object Type:
Report
System:
The UNT Digital Library
Cleanup Verification Package for the 118-F-5 PNL Sawdust Pit
This cleanup verification package documents completion of remedial action, sampling activities, and compliance with cleanup criteria for the 118-F-5 Burial Ground, the PNL (Pacific Northwest Laboratory) Sawdust Pit. The 118-F-5 Burial Ground was an unlined trench that received radioactive sawdust from the floors of animal pens in the 100-F Experimental Animal Farm.
Date:
May 20, 2008
Creator:
Habel, L. D.
Object Type:
Report
System:
The UNT Digital Library
Nevada Test Site-Directed Research and Development, FY 2007 Report
The Nevada Test Site-Directed Research and Development (SDRD) program completed a very successful year of research and development activities in FY 2007. Twenty-nine new projects were selected for funding this year, and eight projects started in FY 2006 were brought to conclusion. The total funds expended by the SDRD program were $5.67 million, for an average per-project cost of $153 thousand. An external audit conducted in September 2007 verified that appropriate accounting practices were applied to the SDRD program. Highlights for the year included: programmatic adoption of 8 SDRD-developed technologies; the filing of 9 invention disclosures for innovation evolving from SDRD projects; participation in the tri-Lab Laboratory Directed Research and Development (LDRD) and SDRD Symposium that was broadly attended by Nevada Test Site (NTS), National Nuclear Security Administration (NNSA), LDRD, U.S. Department of Homeland Security (DHS), and U.S. Department of Defense (DoD) representatives; peer reviews of all FY 2007 projects; and the successful completion of 37 R&D projects, as presented in this report. In response to a company-wide call, authors throughout the NTS complex submitted 182 proposals for FY 2007 SDRD projects. The SDRD program has seen a dramatic increase in the yearly total of submitted proposals--from 69 in FY …
Date:
February 20, 2008
Creator:
Wil Lewis, editor
Object Type:
Report
System:
The UNT Digital Library
Searching for Jets in Heavy Ion Collisions
Jet quenching measurements using leading particles and their correlations suffer from known biases, which can be removed via direct reconstruction of jets in central heavy ion collisions. In this talk, we discuss several modern jet reconstruction algorithms and background subtraction techniques that are appropriate to heavy ion collisions.
Date:
June 20, 2008
Creator:
Salur, Sevil
Object Type:
Article
System:
The UNT Digital Library
Bonding, Backbonding, and Spin-Polarized Molecular Orbitals:Basis for Magnetism and Semiconducting Transport in V[TCNE]x~;;2
X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L2,3 and C and N K edges reveal bonding/backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x~;;2. In V spectra, dxy-like orbitals are modeled assuming V2+ in an octahedral ligand field, while dz2 and dx2-y2 orbitals involved in strong covalent bonding cannot be modeled by atomic calculations. C and N MCD, and differences in XAS from neutral TCNE molecules, reveal spin-polarized molecular orbitals in V[TCNE]x~;;2 associated with backbonding interactions that yield its novel properties.
Date:
May 20, 2008
Creator:
Kortright, Jeffrey B.; Lincoln, Derek M.; Edelstein, Ruth Shima & Epstein, Arthur J.
Object Type:
Article
System:
The UNT Digital Library
A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation
The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.
Date:
June 20, 2008
Creator:
London, Dr. Adam
Object Type:
Report
System:
The UNT Digital Library
Modeling of Laser-Induced Metal Combustion
Experiments involving the interaction of a high-power laser beam with metal targets demonstrate that combustion plays an important role. This process depends on reactions within an oxide layer, together with oxygenation and removal of this layer by the wind. We present an analytical model of laser-induced combustion. The model predicts the threshold for initiation of combustion, the growth of the combustion layer with time, and the threshold for self-supported combustion. Solutions are compared with detailed numerical modeling as benchmarked by laboratory experiments.
Date:
February 20, 2008
Creator:
Boley, C D & Rubenchik, A M
Object Type:
Article
System:
The UNT Digital Library
Measurement of Time-Dependent CP Asymmetry in B0 --> KS pi0 gamma Decays
The authors measure the time-dependent CP asymmetry in B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}{gamma} decays for two regions of K{sub S}{sup 0}-{pi}{sup 0} invariant mass, m(K{sub S}{sup 0}{pi}{sup 0}), using the final BABAR data set of 467 x 10{sup 6} B{bar B} pairs collected at the PEP-II e{sup +}e{sup -} collider at SLAC. They find 339 {+-} 24 B{sup 0} {yields} K*{sup 0}{gamma} candidates and measure S{sub K*{gamma}} = -0.03 {+-} 0.29 {+-} 0.03 and C{sub K*{gamma}} = -0.14 {+-} 0.16 {+-} 0.03. In the range 1.1 < m(K{sub S}{sup 0}{pi}{sup 0}) < 1.8 GeV/c{sup 2} they find 133 {+-} 20 B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}{gamma} candidates and measure S{sub K{sub S}{sup 0}{pi}{sup 0}{gamma}} = -0.78 {+-} 0.59 {+-} 0.09 and C{sub K{sub S}{sup 0}{pi}{sup 0}{gamma}} = -0.36 {+-} 0.33 {+-} 0.04. The uncertainties are statistical and systematic, respectively.
Date:
October 20, 2008
Creator:
Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type:
Article
System:
The UNT Digital Library
2006 Savannah River Site Annual Illness and Injury Surveillance Report
The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date:
August 20, 2008
Creator:
United States. Department of Energy. Office of Health, Safety, and Security.
Object Type:
Report
System:
The UNT Digital Library
Progress in L-Band Power Distribution System R&D at SLAC
We report on the L-band RF power distribution system (PDS) developed at SLAC for Fermilab's NML superconducting test accelerator facility. The makeup of the system, which allows tailoring of the power distribution to cavities by pairs, is briefly described. Cold test measurements of the system and the results of high power processing are presented. We also investigate the feasibility of eliminating the expensive, lossy circulators from the PDS by pair-feeding cavities through custom 3-dB hybrids. A computational model is used to simulate the impact on cavity field stability due to the reduced cavity-to-cavity isolation.
Date:
October 20, 2008
Creator:
Nantista, Christopher; Adolphsen, Chris & Wang, Faya
Object Type:
Article
System:
The UNT Digital Library
REPORT ON THE EFFECT OF TEMPERATURE AND AMMONIA CONCENTRATION ON A515 CARBON STEEL IN TANK 241 AY 101 SIMULANT
This report documents the results from RPP-PLAN-38676, Effect of Temperature and Ammonia Concentration on A515 Carbon Steel in Tank 241-AY-101 Simulant. The purpose of this test plan was to investigate the simulant formulated for the double-shell tank (DST) 241 AY 101 (AY 101) with the addition of ammonia. The simulant was formulated from the AY-101 condensate surface layer recipe used by CC Technologies{reg_sign} in the investigation of Hanford DST chemistry, under the Expert Panel on Corrosion. AY-101 is constructed from A515 grade 60 steel. The laboratory investigation used a cylindrical corrosion coupon from this steel formulation with a surface area of 5.64 square centimeters.
Date:
November 20, 2008
Creator:
JB, DUNCAN; DP, FRYE & RB, WYRWAS
Object Type:
Report
System:
The UNT Digital Library
Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery
An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated.
Date:
June 20, 2008
Creator:
Donald C, Energy Concepts Co. & Lauber, Eric, Western Refining Co.
Object Type:
Report
System:
The UNT Digital Library
ELECTROCHEMICAL CORROSION TESTING OF TANKS 241-AN-102 & 241-AP-107 & 241-AP-108 IN SUPPORT OF ULTRASONIC TESTING
This report presents the results of the corrosion rates that were measured using electrochemical methods for tanks 241-AN-102 (AN-102), 241-AP-107 (AP 107), and 241-AP-108 (AP-108) performed under test plant RPP-PLAN-38215. The steel used as materials of construction for AN and AP tank farms was A537 Class 1. Test coupons of A537 Class 1 carbon steel were used for corrosion testing in the AN-107, AP-107, and AP-108 tank waste. Supernate will be tested from AN-102, AP-107, and Ap-108. Saltcake testing was performed on AP-108 only.
Date:
November 20, 2008
Creator:
RB, WYRWAS & JB, DUNCAN
Object Type:
Report
System:
The UNT Digital Library
Final Report PetaScale Application Development Analysis Grant Number DE-FG02-04ER25629
The results obtained from this project will fundamentally change the way we look at computer performance analysis. These results are made possible by the precise definition of a consistent system of measurement with a set of primary units designed specifically for computer performance analysis. This system of units, along with their associated dimensions, allows us to apply the methods of dimensional analysis, based on the Pi Theorem, to define scaling and self-similarity relationships. These relationships reveal new insights into experimental results that otherwise seems only vaguely correlated. Applying the method to cache-miss data revealed scaling relationships that were not seen by those who originally collected the data. Applying dimensional analysis to the performance of parallel numerical algorithms revealed that computational force is a unifying concept for understanding the interaction between hardware and software. The efficiency of these algorithms depends, in a very intimate way, on the balance between hardware forces and software forces. Analysis of five different algorithms showed that performance analysis can be reduced to a study of the differential geometry of the efficiency surface. Each algorithm defines a set of curvilinear coordinates, specific to that algorithm, and different machines follow different paths along the surface depending on the …
Date:
June 20, 2008
Creator:
Numrich, Robert W.
Object Type:
Report
System:
The UNT Digital Library
Field Test Results of Automated Demand Response in a Large Office Building
Demand response (DR) is an emerging research field and an effective tool that improves grid reliability and prevents the price of electricity from rising, especially in deregulated markets. This paper introduces the definition of DR and Automated Demand Response (Auto-DR). It describes the Auto-DR technology utilized at a commercial building in the summer of 2006 and the methodologies to evaluate associated demand savings. On the basis of field tests in a large office building, Auto-DR is proven to be a reliable and credible resource that ensures a stable and economical operation of the power grid.
Date:
October 20, 2008
Creator:
Han, Junqiao; Piette, Mary Ann & Kiliccote, Sila
Object Type:
Article
System:
The UNT Digital Library
Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition
Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The …
Date:
January 20, 2008
Creator:
Sansongsiri, Sakon; Anders, Andre & Yodsombat, Banchob
Object Type:
Article
System:
The UNT Digital Library
Evidence for CP violation in B0 to J/Psi pi0 Decays
None
Date:
August 20, 2008
Creator:
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type:
Article
System:
The UNT Digital Library
Prognostic breast cancer signature identified from 3D culture model accurately predicts clinical outcome across independent datasets
One of the major tenets in breast cancer research is that early detection is vital for patient survival by increasing treatment options. To that end, we have previously used a novel unsupervised approach to identify a set of genes whose expression predicts prognosis of breast cancer patients. The predictive genes were selected in a well-defined three dimensional (3D) cell culture model of non-malignant human mammary epithelial cell morphogenesis as down-regulated during breast epithelial cell acinar formation and cell cycle arrest. Here we examine the ability of this gene signature (3D-signature) to predict prognosis in three independent breast cancer microarray datasets having 295, 286, and 118 samples, respectively. Our results show that the 3D-signature accurately predicts prognosis in three unrelated patient datasets. At 10 years, the probability of positive outcome was 52, 51, and 47 percent in the group with a poor-prognosis signature and 91, 75, and 71 percent in the group with a good-prognosis signature for the three datasets, respectively (Kaplan-Meier survival analysis, p<0.05). Hazard ratios for poor outcome were 5.5 (95% CI 3.0 to 12.2, p<0.0001), 2.4 (95% CI 1.6 to 3.6, p<0.0001) and 1.9 (95% CI 1.1 to 3.2, p = 0.016) and remained significant for the two …
Date:
October 20, 2008
Creator:
Martin, Katherine J.; Patrick, Denis R.; Bissell, Mina J. & Fournier, Marcia V.
Object Type:
Article
System:
The UNT Digital Library
On Yang--Mills Theories with Chiral Matter at Strong Coupling
Strong coupling dynamics of Yang-Mills theories with chiral fermion content remained largely elusive despite much effort over the years. In this work, we propose a dynamical framework in which we can address non-perturbative properties of chiral, non-supersymmetric gauge theories, in particular, chiral quiver theories on S{sub 1} x R{sub 3}. Double-trace deformations are used to stabilize the center-symmetric vacuum. This allows one to smoothly connect smaller(S{sub 1}) to larger(S{sub 1}) physics (R{sub 4} is the limiting case) where the double-trace deformations are switched off. In particular, occurrence of the mass gap in the gauge sector and linear confinement due to bions are analytically demonstrated. We find the pattern of the chiral symmetry realization which depends on the structure of the ring operators, a novel class of topological excitations. The deformed chiral theory, unlike the undeformed one, satisfies volume independence down to arbitrarily small volumes (a working Eguchi-Kawai reduction) in the large N limit. This equivalence, may open new perspectives on strong coupling chiral gauge theories on R{sub 4}.
Date:
August 20, 2008
Creator:
Shifman, M.; /Minnesota U., Theor. Phys. Inst. /Saclay, SPhT; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type:
Article
System:
The UNT Digital Library
Reconstruction from Uniformly Attenuated SPECT Projection Data Using the DBH Method
An algorithm was developed for the two-dimensional (2D) reconstruction of truncated and non-truncated uniformly attenuated data acquired from single photon emission computed tomography (SPECT). The algorithm is able to reconstruct data from half-scan (180o) and short-scan (180?+fan angle) acquisitions for parallel- and fan-beam geometries, respectively, as well as data from full-scan (360o) acquisitions. The algorithm is a derivative, backprojection, and Hilbert transform (DBH) method, which involves the backprojection of differentiated projection data followed by an inversion of the finite weighted Hilbert transform. The kernel of the inverse weighted Hilbert transform is solved numerically using matrix inversion. Numerical simulations confirm that the DBH method provides accurate reconstructions from half-scan and short-scan data, even when there is truncation. However, as the attenuation increases, finer data sampling is required.
Date:
March 20, 2008
Creator:
Huang, Qiu; You, Jiangsheng; Zeng, Gengsheng L. & Gullberg, Grant T.
Object Type:
Article
System:
The UNT Digital Library