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2,104 Matching Results
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Life Cycle Assessment of the Energy Independence and Security Act of 2007: Ethanol - Global Warming Potential and Environmental Emissions
The objective of this study is to use life cycle assessment (LCA) to evaluate the global warming potential (GWP), water use, and net energy value (NEV) associated with the EISA-mandated 16 bgy cellulosic biofuels target, which is assumed in this study to be met by cellulosic-based ethanol, and the EISA-mandated 15 bgy conventional corn ethanol target. Specifically, this study compares, on a per-kilometer-driven basis, the GWP, water use, and NEV for the year 2022 for several biomass feedstocks.
Date:
July 1, 2009
Creator:
Heath, G. A.; Hsu, D. D.; Inman, D.; Aden, A. & Mann, M. K.
Object Type:
Article
System:
The UNT Digital Library
Life Cycle Assessment of Thermal Energy Storage: Two-Tank Indirect and Thermocline
In the United States, concentrating solar power (CSP) is one of the most promising renewable energy (RE) technologies for reduction of electric sector greenhouse gas (GHG) emissions and for rapid capacity expansion. It is also one of the most price-competitive RE technologies, thanks in large measure to decades of field experience and consistent improvements in design. One of the key design features that makes CSP more attractive than many other RE technologies, like solar photovoltaics and wind, is the potential for including relatively low-cost and efficient thermal energy storage (TES), which can smooth the daily fluctuation of electricity production and extend its duration into the evening peak hours or longer. Because operational environmental burdens are typically small for RE technologies, life cycle assessment (LCA) is recognized as the most appropriate analytical approach for determining their environmental impacts of these technologies, including CSP. An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory (NREL) is undertaking an LCA of modern CSP plants, starting with those …
Date:
July 1, 2009
Creator:
Heath, Garvin; Turchi, Craig; Burkhardt, John; Kutscher, Chuck & Decker, Terese
Object Type:
Article
System:
The UNT Digital Library
Low-energy neutrino factory design
The design of a low-energy (4 GeV) neutrino factory (NF) is described, along with its expected performance. The neutrino factory uses a high-energy proton beam to produce charged pions. The {pi}{sup {+-}} decay to produce muons ({mu}{sup {+-}}), which are collected, accelerated, and stored in a ring with long straight sections. Muons decaying in the straight sections produce neutrino beams. The scheme is based on previous designs for higher energy neutrino factories, but has an improved bunching and phase rotation system, and new acceleration, storage ring, and detector schemes tailored to the needs of the lower energy facility. Our simulations suggest that the NF scheme we describe can produce neutrino beams generated by {approx} 1.4 x 10{sup 21} {mu}{sup +} per year decaying in a long straight section of the storage ring, and a similar number of {mu}{sup -} decays.
Date:
July 1, 2009
Creator:
Ankenbrandt, C.; Bogacz, S. A.; Bross, A.; Geer, S.; Johnstone, C.; Neuffer, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Machine Studies During Beam Commissioning of the SPS-to-LHC Transfer Lines
Through May to September 2008, further beam commissioning of the SPS-to-LHC transfer lines was performed. For the first time, optics and dispersion measurements were also taken in the last part of the lines, and into the LHC. Extensive trajectory and optics studies were conducted, in parallel with hardware checks. In particular dispersion measurements and their comparison with the beam line model were analysed in detail and led to propose the addition of a dispersion-free steering algorithm in the existing trajectory correction program. Its effectiveness was simulated and is briefly discussed.
Date:
July 1, 2009
Creator:
Meddahi, M.; Agapov, I.; Fuchsberger, K.; Goddard, B.; Herr, W.; Kain, V. et al.
Object Type:
Article
System:
The UNT Digital Library
Managing the Nuclear Fuel Cycle: Policy Implications of Expanding Global Access to Nuclear Power
After several decades of widespread stagnation, nuclear power is attracting renewed interest. Expanding global access to nuclear power has the potential to lead to the spread of nuclear technology that could be used for nuclear weapons. This report discusses the issue of nuclear power with regard to nuclear weapons nonproliferation policies, the Global Nuclear Energy Partnership (GNEP) begun under the Bush Administration, the future of the GNEP under the Obama Administration, and four areas of oversight in which Congress will have a considerable role.
Date:
July 1, 2009
Creator:
Nikitin, Mary Beth; Andrews, Anthony & Holt, Mark
Object Type:
Report
System:
The UNT Digital Library
Managing the Nuclear Fuel Cycle: Policy Implications of Expanding Global Access to Nuclear Power
This report begins with a look at the motivating factors underlying the resurgent interest in nuclear power, the nuclear power industry's current state of affairs, and the interdependence of the various stages of the nuclear fuel cycle. A number of proposals have been offered that are aimed at limiting direct participation in the global nuclear fuel industry by assuring access to nuclear fuel supplies.
Date:
July 1, 2009
Creator:
Nikitin, M. B.; Andrews, Anthony & Holt, Mark
Object Type:
Report
System:
The UNT Digital Library
Mannford Eagle (Mannford, Okla.), Vol. 28, No. 6, Ed. 1 Wednesday, July 1, 2009
Weekly newspaper from Mannford, Oklahoma that includes local, state, and national news along with advertising.
Date:
July 1, 2009
Creator:
Hughes, Dustin
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Market Assessment of Biomass Gasification and Combustion Technology for Small- and Medium-Scale Applications
This report provides a market assessment of gasification and direct combustion technologies that use wood and agricultural resources to generate heat, power, or combined heat and power (CHP) for small- to medium-scale applications. It contains a brief overview of wood and agricultural resources in the U.S.; a description and discussion of gasification and combustion conversion technologies that utilize solid biomass to generate heat, power, and CHP; an assessment of the commercial status of gasification and combustion technologies; a summary of gasification and combustion system economics; a discussion of the market potential for small- to medium-scale gasification and combustion systems; and an inventory of direct combustion system suppliers and gasification technology companies. The report indicates that while direct combustion and close-coupled gasification boiler systems used to generate heat, power, or CHP are commercially available from a number of manufacturers, two-stage gasification systems are largely in development, with a number of technologies currently in demonstration. The report also cites the need for a searchable, comprehensive database of operating combustion and gasification systems that generate heat, power, or CHP built in the U.S., as well as a national assessment of the market potential for the systems.
Date:
July 1, 2009
Creator:
Peterson, D. & Haase, S.
Object Type:
Report
System:
The UNT Digital Library
Measurement and Characterization of Nuclear Material at Idaho National Laboratory
A measurement plan and preliminary Monte Carlo simulations are presented for the investigation of well-defined mixed-oxide fuel pins. Measurement analysis including pulse-height distributions and time-dependent cross-correlation functions will be performed separately for neutrons and gamma rays. The utilization of Monte Carlo particle transport codes, specifically MCNP-PoliMi, is discussed in conjunction with the anticipated measurements. Four EJ-309 liquid scintillation detectors with an accurate pulse timing and digital, offline, optimized pulse-shape discrimination method will be used to prove the dependency of pulse-height distributions, cross-correlation functions, and material multiplicities upon fuel pin composition, fuel pin quantity, and detector geometry. The objective of the measurements and simulations is to identify novel methods for describing mixed-oxide fuel samples by relating measured quantities to fuel characteristics such as criticality, mass quantity, and material composition. This research has applications in nuclear safeguards and nonproliferation.
Date:
July 1, 2009
Creator:
Dolan, J. L.; Flaska, M.; Pozzi, S. A. & Chichester, D. L.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the double differential diject mass cross section in pp(bar) collisions at sqrt(s) = 1.96 TeV
This thesis presents the analysis of the double differential dijet mass cross section, measured at the D0 detector in Batavia, IL, using p{bar p} collisions at a center of mass energy of {radical}s = 1.96 TeV. The dijet mass was calculated using the two highest p{sub T} jets in the event, with approximately 0.7 fb{sup -1} of data collected between 2004 and 2005. The analysis was presented in bins of dijet mass (M{sub JJ}) and rapidity (y), and extends the measurement farther in M{sub JJ} and y than any previous measurement. Corrections due to detector effects were calculated using a Monte Carlo simulation and applied to data. The errors on the measurement consist of statistical and systematic errors, of which the Jet Energy Scale was the largest. The final result was compared to next-to-leading order theory and good agreement was found. These results may be used in the determination of the proton parton distribution functions and to set limits on new physics.
Date:
July 1, 2009
Creator:
Rominsky, Mandy Kathleen
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Measurement of the t-channel single top quark production cross section
The D0 collaboration reports direct evidence for electroweak production of single top quarks through the t-channel exchange of a virtual W boson. This is the first analysis to isolate an individual single top quark production channel. We select events containing an isolated electron or muon, missing transverse energy, and two, three or four jets from 2.3 fb{sup -1} of p{bar p} collisions at the Fermilab Tevatron Collider. One or two of the jets are identified as containing a b hadron. We combine three multivariate techniques optimized for the t-channel process to measure the t- and s-channel cross sections simultaneously. We measure cross sections of 3.14{sub -0.80}{sup +0.94} pb for the t-channel and 1.05 {+-} 0.81 pb for the s-channel. The measured t-channel result is found to have a significance of 4.8 standard deviations and is consistent with the standard model prediction.
Date:
July 1, 2009
Creator:
Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of trilinear gauge boson couplings from at {\boldmath$\sqrt{s}=1.96$} TeV
We present a direct measurement of trilinear gauge boson couplings at gammaWW and ZWW vertices in WW and WZ events produced in p{bar p} collisions at {radical}s = 1.96 TeV. We consider events with one electron or muon, missing transverse energy, and at least two jets. The data were collected using the D0 detector and correspond to 1.1 fb{sup -1} of integrated luminosity. Considering two different relations between the couplings at the gammaWW and ZWW vertices, we measure these couplings at 68% C.L. to be kappa{sub gamma} = 1.07{sub -0.29}{sup +0.26}, lambda = 0.00{sub -0.06}{sup +0.06}, and g{sub 1}{sup Z} = 1.04{sup -0.09}{sup +0.09} in a scenario respecting SU(2){sub L}[direct-product]U(1){sub Y} gauge symmetry and kappa = 1.04{sub -0.11}{sup +0.11} and lambda=0.00{sub -0.06}{sup +0.06} in an 'equal couplings' scenario.
Date:
July 1, 2009
Creator:
Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of Z/gamma*+jet+X angular distributions in p anti-p collisions at s**(1/2) = 1.96.TeV
We present the first measurements at a hadron collider of differential cross sections for Z/{gamma}* + jet + X production in {Delta}{phi}(Z, jet), |{Delta}y(Z, jet)| and |y{sub boost}(Z + jet)|. Vector boson production in association with jets is an excellent probe of QCD and constitutes the main background to many small cross section processes, such as associated Higgs production. These measurements are crucial tests of the predictions of perturbative QCD and current event generators, which have varied success in describing the data. Using these measurements as inputs in tuning event generators will increase the experimental sensitivity to rare signals.
Date:
July 1, 2009
Creator:
Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd et al.
Object Type:
Article
System:
The UNT Digital Library
Measurements of the operating characteristics of a 1064 nm pumped KTP RISTRA OPO.
Measurements of the operating characteristics of a 1064 nm pumped potassium titanyl phosphte (KTP) optical parametric oscillator (OPO) were carried out at the Electro Optics Systems Laboratory of Georgia Tech Research Institute (GTRI). The OPO was developed by Sandia National Laboratories and employs a nonplanar image-rotating geometry that is known by the acronym RISTRA, denoting Rotated Image Singly-Resonant Twisted RectAngle. The OPO was configured for pumping by the 1064 nm fundamental wavelength of a Q-switched Nd:YAG laser to generate a signal wavelength at 1627 nm and idler wavelength at 3074.8 nm. GTRI will be incorporate the OPO into a multi-wavelength lidar platform called the Integrated Atmospheric Characterization System (IACS). Prior to completion of the system design for the IACS platform, personnel at GTRI carried out a series of risk reduction experiments to measure the operating characteristics of the OPO. Sandia's role in this effort included technical assistance with numerical modeling of OPO performance, selection of nonlinear optical crystals, specification of cavity-mirror dielectric coatings, selection of vendors for optical components, and advice concerning integration of the RISTRA OPO into the IACS platform. This report describes results of the risk reduction measurements and it also provides some background information on the operating …
Date:
July 1, 2009
Creator:
Gimmestad, Gary (Georgia Tech Research Institute, Atlanta, GA); Armstrong, Darrell Jewell; Wood, Jack (Georgia Tech Research Institute, Atlanta, GA) & Roberts, David (Georgia Tech Research Institute, Atlanta, GA)
Object Type:
Report
System:
The UNT Digital Library
The Mercedes Enterprise (Mercedes, Tex.), Vol. 101, No. 26, Ed. 1 Wednesday, July 1, 2009
Weekly newspaper from Mercedes, Texas that includes local, state, and national news along with advertising.
Date:
July 1, 2009
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Mesa Top Photovoltaic Array (Fact Sheet)
Fact sheet overview of the Mesa Top Photovoltaic Array project implemented by the Department of Energy Golden Office and National Renewable Energy Laboratory.
Date:
July 1, 2009
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Metrics for border management systems.
There are as many unique and disparate manifestations of border systems as there are borders to protect. Border Security is a highly complex system analysis problem with global, regional, national, sector, and border element dimensions for land, water, and air domains. The complexity increases with the multiple, and sometimes conflicting, missions for regulating the flow of people and goods across borders, while securing them for national security. These systems include frontier border surveillance, immigration management and customs functions that must operate in a variety of weather, terrain, operational conditions, cultural constraints, and geopolitical contexts. As part of a Laboratory Directed Research and Development Project 08-684 (Year 1), the team developed a reference framework to decompose this complex system into international/regional, national, and border elements levels covering customs, immigration, and border policing functions. This generalized architecture is relevant to both domestic and international borders. As part of year two of this project (09-1204), the team determined relevant relative measures to better understand border management performance. This paper describes those relative metrics and how they can be used to improve border management systems.
Date:
July 1, 2009
Creator:
Duggan, Ruth Ann
Object Type:
Report
System:
The UNT Digital Library
MiniBooNE Oscillation Results
These proceedings summarize the MiniBooNE {nu}{sub {mu}} {yields} {nu}{sub e} results, describe the first {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} result, and current analysis effort with the NuMI neutrinos detected in the miniBooNE detector.
Date:
July 1, 2009
Creator:
Djurcic, Zelimir
Object Type:
Article
System:
The UNT Digital Library
Multi-muon events at CDF
We report a study of multi-muon events produced at the Fermilab Tevatron collider and recorded by the CDF II detector. In a data set acquired with a dedicated dimuon trigger and corresponding to an integrated luminosity of 2100 pb{sup -1}, we isolate a significant sample of events in which at least one of the identified muons has large impact parameter and is produced outside the beam pipe of radius 1.5 cm. We are unable to fully account for the number and properties of the events through standard model processes in conjunction with our current understanding of the CDF II detector, trigger and event reconstruction. Several topological and kinematic properties of these events are also presented. In contrast, the production cross section and kinematics of events in which both muon candidates are produced inside the beam pipe are successfully modeled by known QCD processes which include heavy flavor production. The presence of these anomalous multi-muon events offers a plausible resolution to long-standing inconsistencies related to b{bar b} production and decay.
Date:
July 1, 2009
Creator:
Ptochos, F. & U., /Cyprus
Object Type:
Article
System:
The UNT Digital Library
Nanostructural engineering of nitride nucleation layers for GaN substrate dislocation reduction.
With no lattice matched substrate available, sapphire continues as the substrate of choice for GaN growth, because of its reasonable cost and the extensive prior experience using it as a substrate for GaN. Surprisingly, the high dislocation density does not appear to limit UV and blue LED light intensity. However, dislocations may limit green LED light intensity and LED lifetime, especially as LEDs are pushed to higher current density for high end solid state lighting sources. To improve the performance for these higher current density LEDs, simple growth-enabled reductions in dislocation density would be highly prized. GaN nucleation layers (NLs) are not commonly thought of as an application of nano-structural engineering; yet, these layers evolve during the growth process to produce self-assembled, nanometer-scale structures. Continued growth on these nuclei ultimately leads to a fully coalesced film, and we show in this research program that their initial density is correlated to the GaN dislocation density. In this 18 month program, we developed MOCVD growth methods to reduce GaN dislocation densities on sapphire from 5 x 10{sup 8} cm{sup -2} using our standard delay recovery growth technique to 1 x 10{sup 8} cm{sup -2} using an ultra-low nucleation density technique. For this …
Date:
July 1, 2009
Creator:
Koleske, Daniel David; Lee, Stephen Roger; Lemp, Thomas Kerr; Coltrin, Michael Elliott; Cross, Karen Charlene & Thaler, Gerald
Object Type:
Report
System:
The UNT Digital Library
A National Tracking Center for Monitoring Shipments of HEU, MOX, and Spent Nuclear Fuel: How do we implement?
Nuclear material safeguards specialists and instrument developers at US Department of Energy (USDOE) National Laboratories in the United States, sponsored by the National Nuclear Security Administration (NNSA) Office of NA-24, have been developing devices to monitor shipments of UF6 cylinders and other radioactive materials , . Tracking devices are being developed that are capable of monitoring shipments of valuable radioactive materials in real time, using the Global Positioning System (GPS). We envision that such devices will be extremely useful, if not essential, for monitoring the shipment of these important cargoes of nuclear material, including highly-enriched uranium (HEU), mixed plutonium/uranium oxide (MOX), spent nuclear fuel, and, potentially, other large radioactive sources. To ensure nuclear material security and safeguards, it is extremely important to track these materials because they contain so-called “direct-use material” which is material that if diverted and processed could potentially be used to develop clandestine nuclear weapons . Large sources could be used for a dirty bomb also known as a radioactive dispersal device (RDD). For that matter, any interdiction by an adversary regardless of intent demands a rapid response. To make the fullest use of such tracking devices, we propose a National Tracking Center. This paper describes what …
Date:
July 1, 2009
Creator:
Schanfein, Mark
Object Type:
Article
System:
The UNT Digital Library
Needed improvements in the development of systemic corrective actions.
There are indications that corrective actions, as implemented at Sandia National Laboratories are not fully adequate. Review of independent audits spanning multiple years provides evidence of recurring issues within the same or similar operations and programs. Several external audits have directly called into question the ability Sandia's assessment and evaluation processes to prevent recurrence. Examples of repeated findings include lockout/tagout programs, local exhaust ventilation controls and radiological controls. Recurrence clearly shows that there are underlying systemic factors that are not being adequately addressed by corrective actions stemming from causal analyses. Information suggests that improvements in the conduct of causal analyses and, more importantly, in the development of subsequent corrective actions are warranted. Current methodolgies include Management Oversight Risk Tree, developed in the early 1970s and Systemic Factors Analysis. Recommendations for improvements include review of other causal analysis systems, training, improved formality of operations, improved documentation, and a corporate method that uses truly systemic solutions. This report was written some years ago and is being published now to form the foundation for current, follow-on reports being developed. Some outdated material is recognized but is retained for report completeness.
Date:
July 1, 2009
Creator:
Campisi, John A.
Object Type:
Report
System:
The UNT Digital Library
Neural Network Based Intrusion Detection System for Critical Infrastructures
Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.
Date:
July 1, 2009
Creator:
Vollmer, Todd; Linda, Ondrej & Manic, Milos
Object Type:
Article
System:
The UNT Digital Library
Neutron Emission Characteristics of Two Mixed-Oxide Fuels: Simulations and Initial Experiments
Simulations and experiments have been carried out to investigate the neutron emission characteristics of two mixed-oxide (MOX) fuels at Idaho National Laboratory (INL). These activities are part of a project studying advanced instrumentation techniques in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and it's Materials Protection, Accounting, and Control for Transmutation (MPACT) campaign. This analysis used the MCNP-PoliMi Monte Carlo simulation tool to determine the relative strength and energy spectra of the different neutron source terms within these fuels, and then used this data to simulate the detection and measurement of these emissions using an array of liquid scintillator neutron spectrometers. These calculations accounted for neutrons generated from the spontaneous fission of the actinides in the MOX fuel as well as neutrons created via (alpha,n) reactions with oxygen in the MOX fuel. The analysis was carried out to allow for characterization of both neutron energy as well as neutron coincidences between multiple detectors. Coincidences between prompt gamma rays and neutrons were also analyzed. Experiments were performed at INL with the same materials used in the simulations to benchmark and begin validation tests of the simulations. Data was collected in these experiments using an array …
Date:
July 1, 2009
Creator:
Chichester, D. L.; Pozzi, S. A.; Dolan, J. L.; Flaska, M.; Johnson, J. T.; Seabury, E. H. et al.
Object Type:
Report
System:
The UNT Digital Library