Production function for short-rotation woody-crop Populus spp. plantations

1994 ◽  
Vol 24 (1) ◽  
pp. 180-184 ◽  
Author(s):  
David A. Lortz ◽  
David R. Betters ◽  
Lynn L. Wright
Keyword(s):  
Production Function ◽  
Cultural Practices ◽  
National Laboratory ◽  
Development Program ◽  
The United States ◽  
Oak Ridge ◽  
Short Rotation ◽  
Wide Range ◽  
Woody Crop ◽  
Populus Spp

Short-rotation woody-crop Populus spp. plantations have the potential to produce large amounts of biomass in short time periods, typically 4–8 years. A production function equation is shown to predict yields for such plantations. The equation is based, in part, on information from biomass production experiments conducted across the United States. These experimental plots are sponsored by the Biofuels Feedstock Development Program of Oak Ridge National Laboratory. The equation uses nine parameters including both cultural practices and climatic and soil site conditions as independent variables. The equation (R2 = 0.86) is accurate and applicable to a wide range of conditions.

Review of Proposed Methodology for Risk-Informed Relaxation to ASME Section XI: Appendix G

2010 ◽  
Author(s):  
Terry Dickson ◽  
Eric Focht ◽  
Mark Kirk
Keyword(s):  
Structural Integrity ◽  
National Laboratory ◽  
The United States ◽  
Pressure Vessels ◽  
Reactor Vessel ◽  
Nuclear Industry ◽  
Oak Ridge ◽  
Wide Range ◽  
Asme Code ◽  
Reactor Pressure

The current regulations, as set forth by the United States Nuclear Regulatory Commission (NRC), to insure that light-water nuclear reactor pressure vessels (RPVs) maintain their structural integrity when subjected to planned normal reactor startup (heat-up) and shut-down (cool-down) transients are specified in Appendix G to 10 CFR Part 50, which incorporates by reference Appendix G to Section XI of the American Society of Mechanical Engineers (ASME) Code. The technical basis for these regulations are now recognized by the technical community as being conservative and some plants are finding it increasingly difficult to comply with the current regulations. Consequently, the nuclear industry has developed, and submitted to the ASME Code for approval, an alternative risk-informed methodology that reduces the conservatism and is consistent with the methods previously used to develop a risk-informed revision to the regulations for accidental transients such as pressurized thermal shock (PTS). The objective of the alternative methodology is to provide a relaxation to the current regulations which will provide more operational flexibility, particularly for reactor pressure vessels with relatively high irradiation levels and radiation sensitive materials, while continuing to provide reasonable assurance of adequate protection to public health and safety. The NRC and its contractor at Oak Ridge National Laboratory (ORNL) have recently performed an independent review of the industry proposed methodology. The NRC / ORNL review consisted of performing probabilistic fracture mechanics (PFM) analyses for a matrix of cool-down and heat-up rates, permutated over various reactor geometries and characteristics, each at multiple levels of embrittlement, including 60 effective full power years (EFPY) and beyond, for various postulated flaw characterizations. The objective of this review is to quantify the risk of a reactor vessel experiencing non-ductile fracture, and possible subsequent failure, over a wide range of normal transient conditions, when the maximum allowable thermal-hydraulic boundary conditions, derived from both the current ASME code and the industry proposed methodology, are imposed on the inner surface of the reactor vessel. This paper discusses the results of the NRC/ORNL review of the industry proposal including the matrices of PFM analyses, results, insights, and conclusions derived from these analyses.

scholarly journals Octane Index Applicability over the Pressure-Temperature Domain

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Tommy R. Powell ◽  
James P. Szybist ◽  
Flavio Dal Forno Chuahy ◽  
Scott J. Curran ◽  
John Mengwasser ◽  
...  
Keyword(s):  
High Efficiency ◽  
National Laboratory ◽  
Operating Conditions ◽  
Dominant Factor ◽  
Compression Ignition ◽  
Oak Ridge ◽  
Operating Modes ◽  
Wide Range ◽  
Thermodynamic Conditions ◽  
Si Engines

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.

Advanced Research and Technology Development Fossil Energy Materials Program

1988 ◽  
Vol 110 (4) ◽  
pp. 670-676
Author(s):  
R. R. Judkins ◽  
R. A. Bradley
Keyword(s):  
Technology Development ◽  
National Laboratory ◽  
Development Program ◽  
Ceramic Composites ◽  
Department Of Energy ◽  
Energy Materials ◽  
Alloy Development ◽  
Fossil Energy ◽  
Oak Ridge ◽  
Research Activities

The Advanced Research and Technology Development (AR&TD) Fossil Energy Materials Program is a multifaceted materials research and development program sponsored by the Office of Fossil Energy of the U.S. Department of Energy. The program is administered by the Office of Technical Coordination. In 1979, the Office of Fossil Energy assigned responsibilities for this program to the DOE Oak Ridge Operations Office (ORO) as the lead field office and Oak Ridge National Laboratory (ORNL) as the lead national laboratory. Technical activities on the program are divided into three research thrust areas: structural ceramic composites, alloy development and mechanical properties, and corrosion and erosion of alloys. In addition, assessments and technology transfer are included in a fourth thrust area. This paper provides information on the structure of the program and summarizes some of the major research activities.

scholarly journals Shared Research Equipment at OAK Ridge National Laboratory

1998 ◽  
Vol 4 (S2) ◽  
pp. 470-471
Author(s):  
N. D. Evans ◽  
E. A. Kenik ◽  
M. K. Miller
Keyword(s):  
Semiconductor Device ◽  
National Laboratory ◽  
Atomic Scale ◽  
Fiscal Year ◽  
Probe Field ◽  
Oak Ridge ◽  
Wide Range ◽  
Oak Ridge National Laboratory ◽  
Electron Microscopes ◽  
Research Equipment

The Shared Research Equipment (SHaRE) User Facility and Program at Oak Ridge National Laboratory (ORNL) provides microanalytical facilities for studies within the materials sciences. Available instrumentation includes advanced analytical electron microscopes, atom probe field ion microscopes, and nanoindentation facilities. Through SHaRE, researchers from U.S. universities, industries, and government laboratories may collaborate with Facility scientists to perform research not possible at their home institutions. International collaborations are also possible. Most SHaRE projects seek correlations at the microscopic or atomic scale between structure and properties in a wide range of metallic, ceramic, and other structural materials. Typical research projects include studies of magnetic materials, advanced alloys, catalysts, semiconductor device materials, high Tc superconductors, and surface-modified polymers. Projects usually involve one or more external researchers visiting the SHaRE Facility for up to three weeks during the fiscal year (October 1 - September 30). Project approval is based upon the scientific excellence and relevance of proposed collaborative research.

Building the TeraGrid

2005 ◽  
Vol 363 (1833) ◽  
pp. 1715-1728 ◽  
Author(s):  
Peter H Beckman
Keyword(s):  
High Performance ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
The United States ◽  
Parallel Computer ◽  
Software Environment ◽  
Distributed Resources ◽  
Oak Ridge ◽  
California Institute Of Technology ◽  
Institute Of Technology

On 1 October 2004, the most ambitious high-performance Grid project in the United States—the TeraGrid—became fully operational. Resources at nine sites—the San Diego Supercomputer Center, the California Institute of Technology, the National Center for Supercomputing Applications, the University of Chicago/Argonne National Laboratory, Pittsburgh Supercomputing Center, Texas Advanced Computing Center, Purdue University, Indiana University and Oak Ridge National Laboratory—were joined via an ultra-fast optical network, unified policies and security procedures and a sophisticated distributed computing software environment. Funded by the National Science Foundation, the TeraGrid enables scientists and engineers to combine distributed, multiple data sources with computation at any of the sites or link massively parallel computer simulations to extreme-resolution visualizations at remote sites. A single shared utility lets multiple resources be easily leveraged and provides improved access to advanced computational capabilities. One of the demonstrations of this new model for using distributed resources, Teragyroid, linked the infrastructure of the TeraGrid with computing resources in the United Kingdom via a transatlantic data fibre link. Once connected, the software framework of the RealityGrid project was used to successfully explore lattice-Boltzmann simulations involving lattices of over one billion sites.

Creep Strength and Microstructure of AL20-25+Nb Alloy Sheets and Foils for Advanced Microturbine Recuperators

2006 ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Yukinori Yamamoto ◽  
Karren L. More ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Creep Resistance ◽  
National Laboratory ◽  
Rupture Life ◽  
Cost Effective ◽  
Test Facility ◽  
Oak Ridge ◽  
Collaborative Program ◽  
Wide Range

The Oak Ridge National Laboratory (ORNL) and ATI Allegheny-Ludlum began a collaborative program in 2004 to produce a wide range of commercial sheets and foils of the new AL20-25+Nb stainless alloy, specifically designed for advanced microturbine recuperator applications. There is a need for cost-effective sheets/foils with more performance and reliability at 650–750°C than 347 stainless steel, particularly for larger 200–250 kW microturbines. Phase I of this collaborative program produced the sheets and foils needed for manufacturing brazed plated-fin (BPF) aircells, while Phase II provided foils for primary surface (PS) aircells, and modified processing to change the microstructure of sheets and foils for improved creep-resistance. Phase I sheets and foils of AL20-25+Nb have much more creep-resistance than 347 steel at 700–750°C, and foils are slightly stronger than HR120 and HR230. Preliminary results for Phase II show nearly double the creep-rupture life of sheets at 750°C/100 MPa, with the first foils tested approaching the creep resistance of alloy 625 foils. AL20-25+Nb alloy foils are also now being tested in the ORNL Recuperator Test Facility.

Probabilistic Structural Mechanics Analysis of the Degraded Davis-Besse RPV Head

2006 ◽  
Author(s):  
Paul T. Williams ◽  
Shengjun (Sean) Yin ◽  
B. Richard Bass
Keyword(s):  
National Laboratory ◽  
Damage Model ◽  
The United States ◽  
Structural Mechanics ◽  
Companion Paper ◽  
Experimental Program ◽  
Oak Ridge ◽  
Steel Technology ◽  
Sensitivity Studies ◽  
Technical Basis

The Heavy-Section Steel Technology (HSST) Program at Oak Ridge National Laboratory (ORNL) performed a probabilistic structural mechanics (PSM) analysis of the damaged Davis Besse reactor pressure vessel head in support of the United States Nuclear Regulatory Commission’s ongoing forensic investigations. This paper presents a summary of the results of that PSM analysis, including a description of the Davis-Besse wastage-area damage model, the technical basis for the model, and the results of sensitivity studies based on a cladding capacity analysis (CCA) and an Accident Sequence Precursor (ASP) investigation of the wastage cavity. A companion paper describes the HSST experimental program carried out at ORNL in parallel with the PSM analysis.

Effects of Chemical Content Variation on the Fracture Probability of PWR Pressure Vessel Subjected to PTS Events

2015 ◽  
Author(s):  
Pin-Chiun Huang ◽  
Hsoung-Wei Chou ◽  
Yuh-Ming Ferng
Keyword(s):  
Pressure Vessel ◽  
National Laboratory ◽  
Nickel Content ◽  
The United States ◽  
Fracture Probability ◽  
Pressure Vessels ◽  
Pressurized Water ◽  
Oak Ridge ◽  
Content Variation ◽  
Chemical Content

This paper is to study the effects of copper and nickel content variations on the fracture probability of the pressurized water reactor (PWR) pressure vessel subjected to pressurized-thermal-shock (PTS) transients. The probabilistic fracture mechanics (PFM) code, FAVOR, which was developed by the Oak Ridge National Laboratory in the United States, is employed to perform the analyses. A Taiwan domestic PWR pressure vessel with varied copper and nickel contents of beltline region welds and plates is investigated in the study. Some PTS transients analyzed from Beaver Valley Unit 1 for establishing the USNRC’s new PTS rule are applied as the loading conditions. It is found that the content variation of copper and nickel will significantly affect the radiation embrittlement and the fracture probability of PWR pressure vessels. The results can be regarded as the risk incremental factors for comparison with the safety regulation requirements on vessel degradation as well as a reference for the operation of PWR plants in Taiwan.

Z-Contrast Imaging of Grain Boundaries in Semiconductors

1996 ◽  
Vol 54 ◽  
pp. 332-333
Author(s):  
M. F. Chisholm ◽  
S. J. Pennycook
Keyword(s):  
Grain Boundaries ◽  
Chemical Potential ◽  
National Laboratory ◽  
Atomic Scale ◽  
Structural Defects ◽  
Specimen Thickness ◽  
Contrast Imaging ◽  
Oak Ridge ◽  
Wide Range ◽  
Annular Detector

Interest in grain boundaries in semiconductors is linked to the application of polycrystalline semiconductors as photovoltaic and interconnect materials. In real devices such as solar cells and MOS structures as well as future devices such as flat-panel displays, the intergranular regions of the polycrystalline solid have a significant effect on the flow of electronic current. These grain boundary barriers exist because the chemical potential of the boundary atoms are shifted from the bulk value by the change in local symmetry. The chemical potential is also changed by impurities, other structural defects, and other phases in the boundary. The lack of knowledge on the atomic structure of grain boundaries is, at present, the greatest barrier to advancements in the understanding of the electrical properties of these defects.The advances of the last few years have provided the tools with which to probe these interfaces at the true atomic scale. One such tool is the high-resolution scanning transmission electron microscope installed at Oak Ridge National Laboratory (VG Microscopes HB603) that can form a 1.27Å electron probe. Images are formed by scanning the probe across a thin sample and using an annular detector to collect electrons scattered to high angles. Because the annular detector collects electrons scattered over a wide range of angles, phase correlations and dynamical diffraction effects are averaged by this annular integration. Thus, an image with incoherent characteristics is produced and retained to relatively large specimen thickness.

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