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ADVANCED RADIOISOTOPE HEAT SOURCE AND PROPULSION SYSTEMS FOR PLANETARY EXPLORATION (open access)

ADVANCED RADIOISOTOPE HEAT SOURCE AND PROPULSION SYSTEMS FOR PLANETARY EXPLORATION

The exploration of planetary surfaces and atmospheres may be enhanced by increasing the range and mobility of a science platform. Fundamentally, power production and availability of resources are limiting factors that must be considered for all science and exploration missions. A novel power and propulsion system is considered and discussed with reference to a long-range Mars surface exploration mission with in-situ resource utilization. Significance to applications such as sample return missions is also considered. Key material selections for radioisotope encapsulation techniques are presented.
Date: September 1, 2010
Creator: O'Brien, R. C.; Howe, S. D. & Werner, J. E.
System: The UNT Digital Library
Advanced Unit Commitment Strategies for the U.S. Eastern Interconnection: Preprint (open access)

Advanced Unit Commitment Strategies for the U.S. Eastern Interconnection: Preprint

This paper outlines a study undertaken for the U.S. Eastern Interconnection in which different advanced unit commitment strategies were simulated for three different years to evaluate the benefits that may occur from using these strategies as an operational tool.
Date: October 1, 2010
Creator: Ela, E.; Milligan, M.; Meibom, P.; Barth, R. & Tuohy, A.
System: The UNT Digital Library
ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS (open access)

ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.
Date: May 12, 2010
Creator: Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J et al.
System: The UNT Digital Library
Advances in Modeling Exploding Bridgewire Initiation (open access)

Advances in Modeling Exploding Bridgewire Initiation

There is great interest in applying magnetohydrodynamic (MHD) simulation techniques to the designs of electrical high explosive (HE) initiators, for the purpose of better understanding a design's sensitivities, optimizing its performance, and/or predicting its useful lifetime. Two MHD-capable LLNL codes, CALE and ALE3D, are being used to simulate the process of ohmic heating, vaporization, and plasma formation in exploding bridgewires (EBW). Initiation of the HE is simulated using Ignition & Growth reactive flow models. 1-D, 2-D and 3-D models have been constructed and studied. The models provide some intuitive explanation of the initiation process and are useful for evaluating the potential impact of identified aging mechanisms (such as the growth of intermetallic compounds or powder sintering). The end product of this work is a simulation capability for evaluating margin in proposed, modified or aged initiation system designs.
Date: March 10, 2010
Creator: Hrousis, C A & Christensen, J S
System: The UNT Digital Library
ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS (open access)

ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS

Reactive tracers have long been considered a possible means of measuring thermal drawdown in a geothermal system, before significant cooling occurs at the extraction well. Here, we examine the sensitivity of the proposed method to evaluate reservoir cooling and demonstrate that while the sensitivity of the method as generally proposed is low, it may be practical under certain conditions.
Date: October 1, 2010
Creator: Plummer, Mitchell A.; Palmer, Carl D.; Mattson, Earl D.; Redden, George D. & Hull, Laurence C.
System: The UNT Digital Library
Advancing Wind Integration Study Methodologies: Implications of Higher Levels of Wind (open access)

Advancing Wind Integration Study Methodologies: Implications of Higher Levels of Wind

The authors report on the evolution of techniques to better model high penetrations (generally, 20% or more energy penetration) of wind energy.
Date: July 1, 2010
Creator: Milligan, M.; Ela, E.; Lew, D.; Corbus, D. & Wan, Y. H.
System: The UNT Digital Library
Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments (open access)

Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments

None
Date: December 21, 2010
Creator: Le Galloudec, N. R.; Cobble, J.; Nelson, S. L.; Merwin, A.; Paudel, Y.; Shrestha, I. et al.
System: The UNT Digital Library
Aerosol-Assisted Solid Debris Collection for the National Ignition Facility (open access)

Aerosol-Assisted Solid Debris Collection for the National Ignition Facility

The National Ignition Facility (NIF) has been completed and has made its first shots on-target. While upcoming experiments will be focused on achieving ignition, a variety of subsequent experiments are planned for the facility, including measurement of cross sections, astrophysical measurements, and investigation of hydrodynamic instability in the target capsule. In order to successfully execute several of these planned experiments, the ability to collect solid debris following a NIF capsule shot will be required. The ability to collect and analyze solid debris generated in a shot at the National Ignition Facility (NIF) will greatly expand the number of nuclear reactions studied for diagnostic purposes. Currently, reactions are limited to only those producing noble gases for cryogenic collection and counting with the Radchem Apparatus for Gas Sampling (RAGS). The radchem solid collection diagnostic has already been identified by NIF to be valuable for the determination and understanding of mix generated in the target capsule's ablation. LLNL is currently developing this solid debris collection capability at NIF, and is in the stage of testing credible designs. Some of these designs explore the use of x-ray generated aerosols to assist in collection of solid debris. However, the variety of harsh experimental conditions this …
Date: May 21, 2010
Creator: Nelson, S. L.; Shaughnessy, D. A.; Moody, K. J.; Ivanov, V. V.; Astanovitskiy, A. L.; Lewis, L. A. et al.
System: The UNT Digital Library
Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data (open access)

Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data

Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth ({tau}{sub a}) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (N{sub d}) compares relatively well to the satellite data at least over the ocean. The relationship between {tau}{sub a} and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (f{sub cld}) and {tau}{sub a} as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the …
Date: March 12, 2010
Creator: Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E. et al.
System: The UNT Digital Library
Aerosol observing system platform integration and AAF instrumentation (open access)

Aerosol observing system platform integration and AAF instrumentation

As part of the federal government’s 2009 American Recovery and Reinvestment Act (ARRA), the U.S. DOE Office of Science allocated funds for the capital upgrade of the Atmospheric Radiation Measurement (ARM) Climate Research Facility to improve and expand observational capabilities related to cloud and aerosol properties. The ARM Facility was established as a national user facility for the global scientific community to conduct a wide range of interdisciplinary science. Part of the ARRA-funded expansion of the ARM Facility includes four new Aerosol Observing Systems (AOS) to be designed, instrumented, and mentored by BNL. The enclosures will be customized SeaTainers. These new platforms ([AMF2]: ARM Mobile Facility-2; [TWP-D]: Tropical Western Pacific at Darwin; and [MAOS-A]/[MAOS-C]: Mobile Aerosol Observing System-Aerosol/-Chemistry) will provide a laboratory environment for fielding instruments to collect data on aerosol life cycle, microphysics, and optical/physical properties. The extensive instrument suite includes both established methods and initial deployments of new techniques to add breadth and depth to the AOS data sets. The platforms are designed: (1) to have all instruments pre-installed before deployment, allowing a higher measurement duty cycle; (2) with a standardized configuration improving the robustness of data inter-comparability; (3) to provide remote access capability for instrument mentors; and …
Date: March 15, 2010
Creator: Springston, S. & Sedlacek, A.
System: The UNT Digital Library
Aerospace and Defense Technologies at BNL (open access)

Aerospace and Defense Technologies at BNL

This presentation gives a brief description of Aerospace and Defense Technologies at BNL.
Date: November 1, 2010
Creator: Elcess, K.
System: The UNT Digital Library
THE AFFECTS OF HALIDE MODIFIERS ON THE SORPTION KINETICS OF THE LI-MG-N-H SYSTEM (open access)

THE AFFECTS OF HALIDE MODIFIERS ON THE SORPTION KINETICS OF THE LI-MG-N-H SYSTEM

In this present work, the affects of different transition metal halides (TiCl{sub 3}, VCl{sub 3}, ScCl{sub 3} and NiCl{sub 2}) on the sorption properties of the 1:1 molar ratio of LiNH{sub 2} to MgH{sub 2} are investigated. The modified mixtures were found to contain LiNH{sub 2}, MgH{sub 2} and LiCl. TGA results showed that the hydrogen desorption temperature was reduced with the modifier addition in this order: TiCl{sub 3}>ScCl{sub 3}>VCl{sub 3}>NiCl{sub 2}. Ammonia release was not significantly reduced resulting in a weight loss greater than the theoretical hydrogen storage capacity of the material. The isothermal sorption kinetics of the modified systems showed little improvement after the first dehydrogenation cycle over the unmodified system but showed drastic improvement in rehydrogenation cycles. XRD and Raman spectroscopy identified the cycled material to be composed of LiH, MgH{sub 2}, Mg(NH{sub 2}){sub 2} and Mg{sub 3}N{sub 2}.
Date: December 16, 2010
Creator: Erdy, C.; Gray, J.; Lascola, R. & Anton, D.
System: The UNT Digital Library
AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE (open access)

AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE

The destabilized complex hydride system composed of LiNH{sub 2}:MgH{sub 2} (1:1 molar ratio) is one of the leading candidates of hydrogen storage with a reversible hydrogen storage capacity of 8.1 wt%. A low sorption enthalpy of {approx}32 kJ/mole H{sub 2} was first predicted by Alapati et al. utilizing first principle density function theory (DFT) calculations and has been subsequently confirmed empirically by Lu et al. through differential thermal analysis (DTA). This enthalpy suggests that favorable sorption kinetics should be obtainable at temperatures in the range of 160 C to 200 C. Preliminary experiments reported in the literature indicate that sorption kinetics are substantially lower than expected in this temperature range despite favorable thermodynamics. Systematic isothermal and isobaric sorption experiments were performed using a Sievert's apparatus to form a baseline data set by which to compare kinetic results over the pressure and temperature range anticipated for use of this material as a hydrogen storage media. Various material preparation methods and compositional modifications were performed in attempts to increase the kinetics while lowering the sorption temperatures. This paper outlines the results of these systematic tests and describes a number of beneficial additions which influence kinetics as well as NH{sub 3} formation.
Date: December 8, 2010
Creator: Erdy, C.; Anton, D. & Gray, J.
System: The UNT Digital Library
eGY-Africa: Addressing the Digital Divide for Science in Africa (open access)

eGY-Africa: Addressing the Digital Divide for Science in Africa

Adoption of information and communication technologies and access to the Internet is expanding in Africa, but because of the rapid growth elsewhere, a Digital Divide between Africa and the rest of the world exists, and the gap is growing. In many sub-Saharan African countries, education and research sector suffers some of the worst deficiencies in access to the Internet, despite progress in development of NRENs - National Research and Education (cyber) Networks. By contrast, it is widely acknowledged in policy statements from the African Union, the UN, and others that strength in this very sector provides the key to meeting and sustaining Millennium Development Goals. Developed countries with effective cyber-capabilities proclaim the benefits to rich and poor alike arising from the Information Revolution. This is but a dream for many scientists in African institutions. As the world of science becomes increasingly Internet-dependent, so they become increasingly isolated. eGY-Africa is a bottom-up initiative by African scientists and their collaborators to try to reduce this Digital Divide by a campaign of advocacy for better institutional facilities. Four approaches are being taken. The present status of Internet services, problems, and plans are being mapped via a combination of direct measurement of Internet performance …
Date: June 16, 2010
Creator: Barton, C. E.; Amory-Mazaudier, C.; Barry, B.; Chukwuma; Cottrell, R. L.; Kalim, U. et al.
System: The UNT Digital Library
AGEING PROCEDURES ON LITHIUM BATTERIES IN AN INTERNATIONAL COLLABORATION CONTEXT (open access)

AGEING PROCEDURES ON LITHIUM BATTERIES IN AN INTERNATIONAL COLLABORATION CONTEXT

The widespread introduction of electrically-propelled vehicles is currently part of many political strategies and introduction plans. These new vehicles, ranging from limited (mild) hybrid to plug-in hybrid to fully-battery powered, will rely on a new class of advanced storage batteries, such as those based on lithium, to meet different technical and economical targets. The testing of these batteries to determine the performance and life in the various applications is a time-consuming and costly process that is not yet well developed. There are many examples of parallel testing activities that are poorly coordinated, for example, those in Europe, Japan and the US. These costs and efforts may be better leveraged through international collaboration, such as that possible within the framework of the International Energy Agency. Here, a new effort is under development that will establish standardized, accelerated testing procedures and will allow battery testing organizations to cooperate in the analysis of the resulting data. This paper reviews the present state-of-the-art in accelerated life testing in Europe, Japan and the US. The existing test procedures will be collected, compared and analyzed with the goal of international collaboration.
Date: November 1, 2010
Creator: Belt, Jeffrey R.; Bloom, Ira; Conte, Mario; Conte, Fiorentino Valerio; Morita, Kenji; Ikeya, Tomohiko et al.
System: The UNT Digital Library
AIR INGRESS ANALYSIS: COMPUTATIONAL FLUID DYNAMIC MODELS (open access)

AIR INGRESS ANALYSIS: COMPUTATIONAL FLUID DYNAMIC MODELS

The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in very high temperature reactors (VHTRs). Phenomena Identification and Ranking Studies to date have ranked an air ingress event, following on the heels of a VHTR depressurization, as important with regard to core safety. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority. Following a loss of coolant and system depressurization incident, air will enter the core of the High Temperature Gas Cooled Reactor through the break, possibly causing oxidation of the in-the core and reflector graphite structure. Simple core and plant models indicate that, under certain circumstances, the oxidation may proceed at an elevated rate with additional heat generated from the oxidation reaction itself. Under postulated conditions of fluid flow and temperature, excessive degradation of the lower plenum graphite can lead to a loss of structural support. Excessive oxidation of core graphite can also lead to the release of fission products into the confinement, which could be detrimental to a reactor safety. Computational fluid dynamic model developed in this …
Date: August 1, 2010
Creator: Oh, Chang H.; Kim, Eung S.; Schultz, Richard; Gougar, Hans; Petti, David & Kang, Hyung S.
System: The UNT Digital Library
Air Shipment of Highly Enriched Uranium Spent Nuclear Fuel from Romania (open access)

Air Shipment of Highly Enriched Uranium Spent Nuclear Fuel from Romania

Romania safely air shipped 23.7 kilograms of Russian origin highly enriched uranium (HEU) spent nuclear fuel from the VVR S research reactor at Magurele, Romania, to the Russian Federation in June 2009. This was the world’s first air shipment of spent nuclear fuel transported in a Type B(U) cask under existing international laws without special exceptions for the air transport licenses. This shipment was coordinated by the Russian Research Reactor Fuel Return Program (RRRFR), part of the U.S. Department of Energy Global Threat Reduction Initiative (GTRI), in cooperation with the Romania National Commission for Nuclear Activities Control (CNCAN), the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), and the Russian Federation State Corporation Rosatom. The shipment was transported by truck to and from the respective commercial airports in Romania and the Russian Federation and stored at a secure nuclear facility in Russia where it will be converted into low enriched uranium. With this shipment, Romania became the 3rd country under the RRRFR program and the 14th country under the GTRI program to remove all HEU. This paper describes the work, equipment, and approvals that were required to complete this spent fuel air shipment.
Date: July 1, 2010
Creator: Allen, K. J.; Bolshinsky, I.; Biro, L. L.; Budu, M. E.; Zamfir, N. V. & Dragusin, M.
System: The UNT Digital Library
AIR SHIPMENT OF HIGHLY ENRICHED URANIUM SPENT NUCLEAR FUEL FROM ROMANIA AND LIBYA (open access)

AIR SHIPMENT OF HIGHLY ENRICHED URANIUM SPENT NUCLEAR FUEL FROM ROMANIA AND LIBYA

In June 2009 Romania successfully completed the world’s first air shipment of highly enriched uranium (HEU) spent nuclear fuel transported in Type B(U) casks under existing international laws and without special exceptions for the air transport licenses. Special 20-foot ISO shipping containers and cask tiedown supports were designed to transport Russian TUK 19 shipping casks for the Romanian air shipment and the equipment was certified for all modes of transport, including road, rail, water, and air. In December 2009 Libya successfully used this same equipment for a second air shipment of HEU spent nuclear fuel. Both spent fuel shipments were transported by truck from the originating nuclear facilities to nearby commercial airports, were flown by commercial cargo aircraft to a commercial airport in Yekaterinburg, Russia, and then transported by truck to their final destinations at the Production Association Mayak facility in Chelyabinsk, Russia. Both air shipments were performed under the Russian Research Reactor Fuel Return Program (RRRFR) as part of the U.S. National Nuclear Security Administration (NNSA) Global Threat Reduction Initiative (GTRI). The Romania air shipment of 23.7 kg of HEU spent fuel from the VVR S research reactor was the last of three HEU fresh and spent fuel shipments …
Date: July 1, 2010
Creator: Landers, Christopher; Bolshinsky, Igor; Allen, Ken & Moses, Stanley
System: The UNT Digital Library
Air Shipment of Spent Nuclear Fuel from Romania to Russia (open access)

Air Shipment of Spent Nuclear Fuel from Romania to Russia

Romania successfully completed the world’s first air shipment of spent nuclear fuel transported in Type B(U) casks under existing international laws and without shipment license special exceptions when the last Romanian highly enriched uranium (HEU) spent nuclear fuel was transported to the Russian Federation in June 2009. This air shipment required the design, fabrication, and licensing of special 20 foot freight containers and cask tiedown supports to transport the eighteen TUK 19 shipping casks on a Russian commercial cargo aircraft. The new equipment was certified for transport by road, rail, water, and air to provide multi modal transport capabilities for shipping research reactor spent fuel. The equipment design, safety analyses, and fabrication were performed in the Russian Federation and transport licenses were issued by both the Russian and Romanian regulatory authorities. The spent fuel was transported by truck from the VVR S research reactor to the Bucharest airport, flown by commercial cargo aircraft to the airport at Yekaterinburg, Russia, and then transported by truck to the final destination in a secure nuclear facility at Chelyabinsk, Russia. This shipment of 23.7 kg of HEU was coordinated by the Russian Research Reactor Fuel Return Program (RRRFR), as part of the U.S. Department …
Date: October 1, 2010
Creator: Bolshinsky, Igor; Allen, Ken; Biro, Lucian & Buchelnikov, Alexander
System: The UNT Digital Library
Alcohol Withdrawal and Brain Injuries: Beyond Classical Mechanisms (open access)

Alcohol Withdrawal and Brain Injuries: Beyond Classical Mechanisms

This review attempts to provide integrated information at the levels of oxidative signaling mechanisms by which ethanol withdrawal (EW) provokes brain injuries and 17β-estradiol (E2) protects against it. Unmanaged sudden withdrawal from the excessive consumption of alcohol (ethanol) adversely alters neuronal integrity in vulnerable brain regions such as the cerebellum, hippocampus, or cortex.
Date: July 20, 2010
Creator: Jung, Marianna E. & Metzger, Daniel B.
System: The UNT Digital Library
Algebraic Multigrid for Linear Systems Obtained by Explicit Element Reduction (open access)

Algebraic Multigrid for Linear Systems Obtained by Explicit Element Reduction

None
Date: June 29, 2010
Creator: Brunner, T. A. & Kolev, T. V.
System: The UNT Digital Library
Algorithm for Computation of Electromagnetic Fields of An Accelerated Short Bunch Inside a Rectangular Chamber (open access)

Algorithm for Computation of Electromagnetic Fields of An Accelerated Short Bunch Inside a Rectangular Chamber

We discuss the feasibility of an application of an implicit finite-difference approximation to calculate the fields of a relativistic bunch moving with no restriction inside a vacuum chamber. We assume that a bunch trajectory is not straight but is inside a vacuum chamber or its branch. The bunch can be deflected by the fields of bending magnets. The bunch can be short enough to produce coherent synchrotron radiation (CSR). Accelerator physicists believe that electromagnetic phenomena of charged beams are governed by Maxwell's equations together with Newton's equations for particle dynamics. To understand the behavior of the beams and radiated fields we just need to find a solution to these equations for the case, which can fully describe the real accelerator environment. So, at first we make a model, which contains all the necessary components, but at the same time can be easily 'inserts' into the equations. Sometimes, it is possible to find analytical solutions, but usually they are only work for one-dimensional cases and rarer for two-dimension cases. To find a solution in general we may transform the equations into a equivalent finite-difference form and solve them using computers. We can find a lot of finite-difference schemes, which approximate Maxwell's …
Date: September 14, 2010
Creator: Novokhatski, Alexander & Sullivan, Michael
System: The UNT Digital Library
Algorithm for precision sub-sample timing between Gaussian like pulses (open access)

Algorithm for precision sub-sample timing between Gaussian like pulses

None
Date: July 20, 2010
Creator: Lerche, R A; Golick, B P; Holder, J P & Kalantar, D H
System: The UNT Digital Library
Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications (open access)

Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications

Improved electrochemical characteristics are observed for Li[Ni1/3Co1/3-yMyMn1/3]O2 cathode materials when M=Ti and y<0.07, compared to the baseline material, with up to 15percent increased discharge capacity.
Date: December 1, 2010
Creator: Kam, Kinson & Doeff, Marca M.
System: The UNT Digital Library