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Traveling waves and the renormalization group improvedBalitsky-Kovchegov equation
I study the incorporation of renormalization group (RG)improved BFKL kernels in the Balitsky-Kovchegov (BK) equation whichdescribes parton saturation. The RG improvement takes into accountimportant parts of the next-to-leading and higher order logarithmiccorrections to the kernel. The traveling wave front method for analyzingthe BK equation is generalized to deal with RG-resummed kernels,restricting to the interesting case of fixed QCD coupling. The resultsshow that the higher order corrections suppress the rapid increase of thesaturation scale with increasing rapidity. I also perform a "diffusive"differential equation approximation, which illustrates that someimportant qualitative properties of the kernel change when including RGcorrections.
Date:
December 1, 2006
Creator:
Enberg, Rikard
Object Type:
Article
System:
The UNT Digital Library
Design and Feasibility Assessment of a Retrospective Epidemiological Study of Coal-Fired Power Plant Emissions in the Pittsburgh Pennsylvania Region
Eighty-nine (89) percent of the electricity supplied in the 35-county Pittsburgh region (comprising parts of the states of Pennsylvania, Ohio, West Virginia, and Maryland) is generated by coal-fired power plants making this an ideal region in which to study the effects of the fine airborne particulates designated as PM{sub 2.5} emitted by the combustion of coal. This report demonstrates that during the period from 1999-2006 (1) sufficient and extensive exposure data, in particular samples of speciated PM{sub 2.5} components from 1999 to 2003, and including gaseous co-pollutants and weather have been collected, (2) sufficient and extensive mortality, morbidity, and related health outcomes data are readily available, and (3) the relationship between health effects and fine particulates can most likely be satisfactorily characterized using a combination of sophisticated statistical methodologies including latent variable modeling (LVM) and generalized linear autoregressive moving average (GLARMA) time series analysis. This report provides detailed information on the available exposure data and the available health outcomes data for the construction of a comprehensive database suitable for analysis, illustrates the application of various statistical methods to characterize the relationship between health effects and exposure, and provides a road map for conducting the proposed study. In addition, a detailed …
Date:
December 20, 2006
Creator:
Bilonick, Richard A.; Connell, Daniel; Talbott, Evelyn; Zborowski, Jeanne & Kim, Myoung
Object Type:
Report
System:
The UNT Digital Library
2003 Climate Change Fuel Cell Buy-Down Program
The Student Apartments Fuel Cell Island Project consists of three (3) 200 kW phosphoric acid fuel cells located in conjunction with three (3) student apartment buildings, each housing 200 students. The Final Report contains limited data because the fuel cells were started up November 2005 and shutdown March 2006. The price of natural gas, which is the primary fuel for the fuel cells, escalated by 200% following hurricane Katrina in August 2005. This escalation in natural gas price made operation of the fuel cells economically unviable, i.e., the cost to produce electricity with the fuel cells far exceeded the cost to purchase electricity from the utility. The College intends to restart the fuel cells once the cost of natural gas stabilizes. The natural gas futures market is currently overpriced even though fundamentally the physical inventory is a five year high. We believe the natural gas market will eventually correct to the fundamentals and drive the cost down. Once this occurs we will restart the fuel cells.
Date:
December 31, 2006
Creator:
Winyard, Lori K.
Object Type:
Report
System:
The UNT Digital Library
Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu
A search for nuclear resonance fluorescence excitations in {sup 235}U and {sup 239}Pu within the energy range of 1.0- to 2.5-MeV was performed using a 4-MeV continuous bremsstrahlung source at the High Voltage Research Laboratory at the Massachusetts Institute of Technology. Measurements utilizing high purity Ge detectors at backward angles identified 9 photopeaks in {sup 235}U and 12 photopeaks in {sup 239}Pu in this energy range. These resonances provide unique signatures that allow the materials to be non-intrusively detected in a variety of environments including fuel cells, waste drums, vehicles and containers. The presence and properties of these states may prove useful in understanding the mechanisms for mixing low-lying collective dipole excitations with other states at low excitations in heavy nuclei.
Date:
December 27, 2006
Creator:
Bertozzi, W.; Caggiano, J. A.; Hensley, W. K.; Johnson, M. S.; Korbly, S. E.; Ledoux, R. J. et al.
Object Type:
Article
System:
The UNT Digital Library
Communal spaces: aggregation and integration in the Mogollon Region of the United States Southwest
Aggregation and integration are processes that occur in human societies throughout the globe. An informative example of population aggregation and social integration can be observed in the North American desert borderlands from A.D. 250 to 1450 in the area known as the Mogollon region. In fact, Mogollon communities oscillated from smaller social groups into larger ones and dispersed into smaller groups only to form larger ones again. For this reason, examining the groups of people living in the Mogollon region provides a magnified view of social change over a substantial period. Understanding patterns of aggregation and integration provides researchers with the promise for research into the nature of these phenomena. In general, the Mogollon region is characterized by limited water supplies and low average annual precipitation. However, pockets of the Mogollon area, including the Mimbres valley and the Gila River valley, represent oases, where permanent rivers and their associated tributaries allowed for the pursuit of agricultural endeavors and access to a wide variety of wild plant and animal resources. The areas with these kinds of potential became population centers for previously dispersed groups of people living in the region. These people exploited natural resources and practiced agriculture in areas surrounding …
Date:
December 1, 2006
Creator:
Nisengard, Jennifer E.
Object Type:
Report
System:
The UNT Digital Library
Terminator Detection by Support Vector Machine Utilizing aStochastic Context-Free Grammar
A 2-stage detector was designed to find rho-independent transcription terminators in the Escherichia coli genome. The detector includes a Stochastic Context Free Grammar (SCFG) component and a Support Vector Machine (SVM) component. To find terminators, the SCFG searches the intergenic regions of nucleotide sequence for local matches to a terminator grammar that was designed and trained utilizing examples of known terminators. The grammar selects sequences that are the best candidates for terminators and assigns them a prefix, stem-loop, suffix structure using the Cocke-Younger-Kasaami (CYK) algorithm, modified to incorporate energy affects of base pairing. The parameters from this inferred structure are passed to the SVM classifier, which distinguishes terminators from non-terminators that score high according to the terminator grammar. The SVM was trained with negative examples drawn from intergenic sequences that include both featureless and RNA gene regions (which were assigned prefix, stem-loop, suffix structure by the SCFG), so that it successfully distinguishes terminators from either of these. The classifier was found to be 96.4% successful during testing.
Date:
December 30, 2006
Creator:
Francis-Lyon, Patricia; Cristianini, Nello & Holbrook, Stephen
Object Type:
Article
System:
The UNT Digital Library
4-D XRD for strain in many grains using triangulation
Determination of the strains in a polycrystalline materialusing 4-D XRD reveals sub-grain and grain-to-grain behavior as a functionof stress. Here 4-D XRD involves an experimental procedure usingpolychromatic micro-beam X-radiation (micro-Laue) to characterizepolycrystalline materials in spatial location as well as with increasingstress. The in-situ tensile loading experiment measured strain in a modelaluminum-sapphire metal matrix composite using the Advanced Light Source,Beam-line 7.3.3. Micro-Laue resolves individual grains in thepolycrystalline matrix. Results obtained from a list of grains sorted bycrystallographic orientation depict the strain states within and amongindividual grains. Locating the grain positions in the planeperpendicular to the incident beam is trivial. However, determining theexact location of grains within a 3-D space is challenging. Determiningthe depth of the grains within the matrix (along the beam direction)involved a triangulation method tracing individual rays that producespots on the CCD back to the point of origin. Triangulation wasexperimentally implemented by simulating a 3-D detector capturingmultiple diffraction images while increasing the camera to sampledistance. Hence by observing the intersection of rays from multiple spotsbelonging to the corresponding grain, depth is calculated. Depthresolution is a function of the number of images collected, grain to beamsize ratio, and the pixel resolution of the CCD. The 4DXRD methodprovides grain morphologies, strain …
Date:
December 31, 2006
Creator:
Bale, Hrishikesh A.; Hanan, Jay C. & Tamura, Nobumichi
Object Type:
Article
System:
The UNT Digital Library
Habilitation Thesis on STT and Higgs searches in WH Rroduction
The detector of the D0 experiment at the proton anti-proton collider Tevatron in Run II is discussed in detail. The performance of the collider and the experiment is presented. Standard model Higgs searches with integrated luminosities between 260 pb{sup -1} and 950 pb{sup -1} and their combination are performed. No deviation from SM background expectation has been observed. Sensitivity prospects at the Tevatron are shown.
Date:
December 1, 2006
Creator:
Sonnenschein, Lars
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Graduate Automotive Technology Education (GATE) Program: Center of Automotive Technology Excellence in Advanced Hybrid Vehicle Technology at West Virginia University
This report summarizes the technical and educational achievements of the Graduate Automotive Technology Education (GATE) Center at West Virginia University (WVU), which was created to emphasize Advanced Hybrid Vehicle Technology. The Center has supported the graduate studies of 17 students in the Department of Mechanical and Aerospace Engineering and the Lane Department of Computer Science and Electrical Engineering. These students have addressed topics such as hybrid modeling, construction of a hybrid sport utility vehicle (in conjunction with the FutureTruck program), a MEMS-based sensor, on-board data acquisition for hybrid design optimization, linear engine design and engine emissions. Courses have been developed in Hybrid Vehicle Design, Mobile Source Powerplants, Advanced Vehicle Propulsion, Power Electronics for Automotive Applications and Sensors for Automotive Applications, and have been responsible for 396 hours of graduate student coursework. The GATE program also enhanced the WVU participation in the U.S. Department of Energy Student Design Competitions, in particular FutureTruck and Challenge X. The GATE support for hybrid vehicle technology enhanced understanding of hybrid vehicle design and testing at WVU and encouraged the development of a research agenda in heavy-duty hybrid vehicles. As a result, WVU has now completed three programs in hybrid transit bus emissions characterization, and WVU …
Date:
December 31, 2006
Creator:
Clark, Nigle N.
Object Type:
Report
System:
The UNT Digital Library
Design of an RFQ-Based Neutron Source for Cargo ContainerInterrogation
An RFQ-based neutron generator system is described that produces pulsed neutrons for the active screening of sea-land cargo containers for the detection of shielded special nuclear materials (SNM). A microwave-driven deuteron source is coupled to an electrostatic LEBT that injects a 40 mA D+ beam into a 6 MeV, 5.1 meter-long 200 MHz RFQ. The RFQ has a unique beam dynamics design and is capable of operating at duty factors of 5 to 10% accelerating a D+ time-averaged current of up to 1.5 mA at 5% duty factor, including species and transmission loss. The beam is transported through a specially-designed thin-window into a 2.5-atmosphere deuterium gas target. A high-frequency dipole magnet is used to scan the beam over the long dimension of the 5 by 35 cm target window. The source will deliver a neutron flux of 1x10$sup 7$ n/(cm$sup 2$s) to the center of an empty cargo container. Details of the ion source, LEBT, RFQ beam dynamics and gas target design are presented.
Date:
December 1, 2006
Creator:
Staples, John W.; Hoff, M. D.; Kwan, J. W.; Li, D.; Ludewigt, B. A.; Ratti, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for Higgs boson production in proton-antiproton collisions at s**(1/2) = 1.96 TeV
We performed a search for Standard Model Higgs boson production in association with W boson (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses the data collected between February 2002 and February 2006 at Collider Detector at Fermilab (CDF), which corresponds to an integrated luminosity of about 1 fb{sup -1}. The experimental final state of WH {yields} {ell}{nu}b{bar b} process is lepton (e{sup {+-}}/{mu}{sup {+-}}), missing transverse energy and two jets. The largest background in lepton+jets events is W+light flavor process, therefore the identification of jets as b-jets reduces this kind of background significantly. We used displaced SECondary VerTeX b-tagging (SECVTX) technique, which utilizes the signature that b-jets have secondary vertex displaced away from primary vertex because of the long life time of B-mesons. However, there is still much contamination in SECVTX b-tagged jets. Finite resolution of secondary vertex tracking measurements results in false tags, and c-jets are also identified as b-jets due to the long life time of D-mesons frequently. For the purpose of increasing the purity of the SECVTX b-tagged jets, we applied Neural Network to SECVTX tagged jets for the first time by using secondary vertex …
Date:
December 1, 2006
Creator:
Kusakabe, Yoshiaki & U., /Waseda
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Non equilibrium dynamics of mixing, oscillations, and equilibration: A model study
The non-equilibrium dynamics of mixing, oscillations and equilibration is studied in a field theory of flavored neutral mesons that effectively models two flavors of mixed neutrinos, in interaction with other mesons that represent a thermal bath of hadrons or quarks and charged leptons. This model describes the general features of neutrino mixing and relaxation via charged currents in a medium. The reduced density matrix and the non-equilibrium effective action that describes the propagation of neutrinos is obtained by integrating out the bath degrees of freedom. We obtain the dispersion relations, mixing angles and relaxation rates of ``neutrino'' quasiparticles. The dispersion relations and mixing angles are of the same form as those of neutrinos in the medium, and the relaxation rates are given by $\Gamma_1(k) = \Gamma_{ee}(k) \cos^2\theta_m(k)+\Gamma_{\mu\mu}(k)\sin^2\theta_m(k); \Gamma_2(k)= \Gamma_{\mu\mu}(k) \cos^2\theta_m(k)+\Gamma_{ee}(k)\sin^2\theta_m(k) $ where $\Gamma_{\alpha\alpha}(k)$ are the relaxation rates of the flavor fields in \emph{absence} of mixing, and $\theta_m(k)$ is the mixing angle in the medium. A Weisskopf-Wigner approximation that describes the asymptotic time evolution in terms of a non-hermitian Hamiltonian is derived. At long time $>>\Gamma^{-1}_{1,2}$ ``neutrinos'' equilibrate with the bath. The equilibrium density matrix is nearly diagonal in the basis of eigenstates of an \emph{effective Hamiltonian that includes self-energy corrections …
Date:
December 22, 2006
Creator:
Ho, Chiu Man; Boyanovsky, D. & Ho, C. M.
Object Type:
Article
System:
The UNT Digital Library
Addressing an Uncertain Future Using Scenario Analysis
The Office of Energy Efficiency and Renewable Energy (EERE) has had a longstanding goal of introducing uncertainty into the analysis it routinely conducts in compliance with the Government Performance and Results Act (GPRA) and for strategic management purposes. The need to introduce some treatment of uncertainty arises both because it would be good general management practice, and because intuitively many of the technologies under development by EERE have a considerable advantage in an uncertain world. For example, an expected kWh output from a wind generator in a future year, which is not exposed to volatile and unpredictable fuel prices, should be truly worth more than an equivalent kWh from an alternative fossil fuel fired technology. Indeed, analysts have attempted to measure this value by comparing the prices observed in fixed-price natural gas contracts compared to ones in which buyers are exposed to market prices (see Bolinger, Wiser, and Golove and (2004)). In addition to the routine reasons for exploring uncertainty given above, the history of energy markets appears to have exhibited infrequent, but troubling, regime shifts, i.e., historic turning points at which the center of gravity or fundamental nature of the system appears to have abruptly shifted. Figure 1 below …
Date:
December 15, 2006
Creator:
Siddiqui, Afzal S. & Marnay, Chris
Object Type:
Report
System:
The UNT Digital Library
Evaluation of OGC Standards for Use in LLNL GIS
None
Date:
December 1, 2006
Creator:
Walker, H; Chou, R M; Chubb, K K & Schek, J L
Object Type:
Article
System:
The UNT Digital Library
High Altitude Aerial Natural Gas Leak Detection System
The objective of this program was to develop and demonstrate a cost-effective and power-efficient advanced standoff sensing technology able to detect and quantify, from a high-altitude (> 10,000 ft) aircraft, natural gas leaking from a high-pressure pipeline. The advanced technology is based on an enhanced version of the Remote Methane Leak Detector (RMLD) platform developed previously by Physical Sciences Inc. (PSI). The RMLD combines a telecommunications-style diode laser, fiber-optic components, and low-cost DSP electronics with the well-understood principles of Wavelength Modulation Spectroscopy (WMS), to indicate the presence of natural gas located between the operator and a topographic target. The transceiver transmits a laser beam onto a topographic target and receives some of the laser light reflected by the target. The controller processes the received light signal to deduce the amount of methane in the laser's path. For use in the airborne platform, we modified three aspects of the RMLD, by: (1) inserting an Erbium-doped optical fiber laser amplifier to increase the transmitted laser power from 10 mW to 5W; (2) increasing the optical receiver diameter from 10 cm to 25 cm; and (3) altering the laser wavelength from 1653 nm to 1618 nm. The modified RMLD system provides a path-integrated …
Date:
December 31, 2006
Creator:
Wainner, Richard T.; Frish, Mickey B.; Green, B. David; Laderer, Matthew C.; Allen, Mark G. & Morency, Joseph R.
Object Type:
Report
System:
The UNT Digital Library
Y-12 Groundwater Protection Program Monitoring Well Inspection and Maintenance Plan
This document is the third revision of the 'Monitoring Well Inspection and Maintenance Plan' for groundwater wells associated with the US Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee. This plan describes the systematic approach for: (1) inspecting the physical condition of monitoring wells at Y-12; (2) identifying maintenance needs that extend the life of the well and assure well-head protection is in place, and (3) identifying wells that no longer meet acceptable monitoring-well design or well construction standards and require plugging and abandonment. The inspection and maintenance of groundwater monitoring wells is one of the primary management strategies of the Y-12 Groundwater Protection Program (GWPP) Management Plan, 'proactive stewardship of the extensive monitoring well network at Y-12' (BWXT 2004a). Effective stewardship, and a program of routine inspections of the physical condition of each monitoring well, ensures that representative water-quality monitoring and hydrologic data are able to be obtained from the well network. In accordance with the Y-12 GWPP Monitoring Optimization Plan (MOP) for Groundwater Monitoring Wells at the Y-12 National Security Complex, Oak Ridge, Tennessee (BWXT 2006b), the status designation (active or inactive) for each well determines the scope and extent of well inspections …
Date:
December 1, 2006
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer
This dissertation presents the highest four-momentum transfer, Q^2,quasielastic (x_Bj = 1) results from Experiment E01-020 which systematically explored the 2He(e,e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q^2 = 0.8, 2.1, and 3.5 GeV^2 and missing momenta, P_miss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, R_LT, and extractoin of the longitudinal-transverse asymmetry, A_LT. This systematic approach will help to understand the reaction mechanism and the deuteron structure down to the short range part of the nucleon-nucleon interaction which is one of the fundamental missions of nuclear physics. By studying the very short distance structure of the deuteron, one may also determine whether or to what extent the description of nuclei in terms of nucleon/meson degrees of freedom must be supplemented by inclusion of explicit quark effects. The unique combination of energy, current, duty factor, and control of systematics for Hall A at Jefferson Lab made Jefferson Lab the only facility in the world where these systematic studies of the deuteron can be undertaken. This is especially true when we want to understand the short range structure of the deuteron where high energies and high luminosity/duty factor are …
Date:
December 31, 2006
Creator:
Ibrahim, Hassan
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Reactive Geochemical Transport Modeling of Concentrated Aqueous Solutions: Supplement to TOUGHREACT User's Guide for the PitzerIon-Interaction Model
In this report, we present: -- The Pitzer ion-interactiontheory and models -- Input file requirements for using the TOUGHREACTPitzer ion-interaction model and associated databases -- Run-time errormessages -- Verification test cases and application examples. For themain code structure, features, overall solution methods, description ofinput/output files for parameters other than those specific to theimplemented Pitzer model, and error messages, see the TOUGHREACT User'sGuide (Xu et al., 2005). The TOUGHREACT Pitzer version runs on aDEC-alpha architecture CPU, under OSF1 V5.1, with Compaq Digital FortranCompiler. The compiler run-time libraries are required for execution aswell as compilation. The code also runs on Intel Pentium IV andhigher-version CPU-based machines with Compaq Visual Fortran Compiler orIntel Fortran Compiler (integrated with the Microsoft DevelopmentEnvironment). The minimum hardware configuration should include 1 GB RAMand 1 GB (2 GB recommended) of available disk space.
Date:
December 15, 2006
Creator:
Zhang, Guoxiang; Spycher, Nicolas; Xu, Tianfu; Sonnenthal, Eric & Steefel , Carl
Object Type:
Report
System:
The UNT Digital Library
Historic American Engineering Record, Idaho National Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex
Just as automobiles need fuel to operate, so do nuclear reactors. When fossil fuels such as gasoline are burned to power an automobile, they are consumed immediately and nearly completely in the process. When the fuel is gone, energy production stops. Nuclear reactors are incapable of achieving this near complete burn-up because as the fuel (uranium) that powers them is burned through the process of nuclear fission, a variety of other elements are also created and become intimately associated with the uranium. Because they absorb neutrons, which energize the fission process, these accumulating fission products eventually poison the fuel by stopping the production of energy from it. The fission products may also damage the structural integrity of the fuel elements. Even though the uranium fuel is still present, sometimes in significant quantities, it is unburnable and will not power a reactor unless it is separated from the neutron-absorbing fission products by a method called fuel reprocessing. Construction of the Fuel Reprocessing Complex at the Chem Plant started in 1950 with the Bechtel Corporation serving as construction contractor and American Cyanamid Company as operating contractor. Although the Foster Wheeler Corporation assumed responsibility for the detailed working design of the overall plant, …
Date:
December 1, 2006
Creator:
Stacy, Susan & Braun, Julie
Object Type:
Report
System:
The UNT Digital Library
Enhancement of Spin-Polarized Electron Emission from Strain-Compensated AlInGaAs-GaAsP Superlattices
Resonance enhancement of the quantum efficiency of new polarized electron photocathodes based on a short-period strain-compensated AlInGaAs/GaAsP superlattice structure is reported. The superlattice is a part of an integrated Fabry-Perot optical cavity. We demonstrate that the Fabry-Perot resonator enhances the quantum efficiency by up to a factor 10 in the wavelength region of the main polarization maximum. The high structural quality implied by these results points to the very promising application of these photocathodes for spin-polarized electron sources.
Date:
December 8, 2006
Creator:
Roberts, J. S.; Yashin, Yu. P.; Mamaev, Yu. A.; Gerchikov, L. G.; Maruyama, T.; Luh, D. -A. et al.
Object Type:
Article
System:
The UNT Digital Library
DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY
Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely used together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced …
Date:
December 28, 2006
Creator:
Cygan, David
Object Type:
Report
System:
The UNT Digital Library
Continuous active-source seismic monitoring of CO2 injection in abrine aquifer
Continuous crosswell seismic monitoring of a small-scale CO2injection was accomplished with the development of a noveltubing-deployed piezoelectric borehole source. This piezotube source wasdeployed on the CO2 injection tubing, near the top of the saline aquiferreservoir at 1657-m depth, and allowed acquisition of crosswellrecordings at 15-minute intervals during the multiday injection. Thechange in traveltime recorded at various depths in a nearby observationwell allowed hour-by-hour monitoring of the growing CO2 plume via theinduced seismic velocity change. Traveltime changes of 0.2 to 1.0 ms ( upto 8 percent ) were observed, with no change seen at control sensorsplaced above the reservoir. The traveltime measurements indicate that theCO2 plume reached the top of the reservoir sand before reaching theobservation well, where regular fluid sampling was occuring during theinjection, thus providing information about the in situ buoyancy ofCO2.
Date:
December 10, 2006
Creator:
Daley, Thomas M.; Solbau, Ray D.; Ajo-Franklin, Jonathan B. & Benson, Sally M.
Object Type:
Article
System:
The UNT Digital Library
Portable, Low-cost NMR with Laser-Lathe Lithography Produced
Nuclear Magnetic Resonance (NMR) is unsurpassed in its ability to non-destructively probe chemical identity. Portable, low-cost NMR sensors would enable on-site identification of potentially hazardous substances, as well as the study of samples in a variety of industrial applications. Recent developments in RF microcoil construction (i.e. coils much smaller than the standard 5 mm NMR RF coils), have dramatically increased NMR sensitivity and decreased the limits-of-detection (LOD). We are using advances in laser pantographic microfabrication techniques, unique to LLNL, to produce RF microcoils for field deployable, high sensitivity NMR-based detectors. This same fabrication technique can be used to produce imaging coils for MRI as well as for standard hardware shimming or 'ex-situ' shimming of field inhomogeneities typically associated with inexpensive magnets. This paper describes a portable NMR system based on a laser-fabricated microcoil and homebuilt probe design. For testing this probe, we used a hand-held 2 kg Halbach magnet that can fit into the palm of a hand, and an RF probe with laser-fabricated microcoils. The focus of the paper is on the evaluation of the microcoils, RF probe, and first generation gradient coils. The setup of this system, initial results, sensitivity measurements, and future plans are discussed. The results, …
Date:
December 21, 2006
Creator:
Herberg, J. L.; Demas, V.; Malba, V.; Bernhardt, A.; Evans, L.; Harvey, C. et al.
Object Type:
Article
System:
The UNT Digital Library
Comparison of AEO 2007 Natural Gas Price Forecast to NYMEX FuturesPrices
On December 5, 2006, the reference case projections from 'Annual Energy Outlook 2007' (AEO 2007) were posted on the Energy Information Administration's (EIA) web site. We at LBNL have, in the past, compared the EIA's reference case long-term natural gas price forecasts from the AEO series to contemporaneous natural gas prices that can be locked in through the forward market, with the goal of better understanding fuel price risk and the role that renewables play in mitigating such risk (see, for example, http://eetd.lbl.gov/ea/EMS/reports/53587.pdf or http://eetd.lbl.gov/ea/ems/reports/54751.pdf). As such, we were curious to see how the latest AEO gas price forecast compares to the NYMEX natural gas futures strip. This brief memo presents our findings. As a refresher, our past work in this area has found that over the past six years, forward natural gas contracts (with prices that can be locked in--e.g., gas futures, swaps, and physical supply) have traded at a premium relative to contemporaneous long-term reference case gas price forecasts from the EIA. As such, we have concluded that, over the past six years at least, levelized cost comparisons of fixed-price renewable generation with variable-price gas-fired generation that have been based on AEO natural gas price forecasts (rather than …
Date:
December 6, 2006
Creator:
Bolinger, Mark & Wiser, Ryan
Object Type:
Report
System:
The UNT Digital Library