Microstructure of a sample of Inconel X-750 damaged by ISCC (intergranular stress corrosion cracking) was examined after fatigue precracking in a high-temperature environment of deaerated water. Orientation imaging microscopy was used to reveal the microstructure adjacent to the crack path. General high-angle boundaries were found to be most susceptible to cracking. An ordering of the susceptibilities to ISCC damage was proposed; all boundaries have been classified into one of 12 categories. A model is proposed to predict the crack path for ISCC based on ex situ record of damage probabilities. The cracking is modeled as a Markov chain on a regular hexagonal array of grain boundaries representing the connectivity of the network.

Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditions as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%).

The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.

The objective of this Stage Gate IV project was to test and substantiate the viability of an erosion‐resistant nanocoating for application on compressor airfoils for gas turbines in both industrial power generation and commercial aviation applications. To effectively complete this project, the National Energy Technology Laboratory’s Office of Research & Development teamed with MDS Coating Technologies Inc. (MCT), Delta Air Lines ‐ Technical Operations Division (Delta Tech Ops), and Calpine Corporation. The coating targeted for this application was MCT’s Next Generation Coating, version 4 (NGC‐v4 ‐ with the new registered trademark name of BlackGold®). The coating is an erosion and corrosion resistant composite nanostructured coating. This coating is comprised of a proprietary ceramic‐metallic nano‐composite construction which provides enhanced erosion resistance and also retains the aerodynamic geometry of the airfoils. The objective of the commercial aviation portion of the project was to substantiate the coating properties to allow certification from the FAA to apply an erosion‐resistant coating in a commercial aviation engine. The goal of the series of tests was to demonstrate that the durability of the airfoils is not affected negatively with the application of the NGC v4 coating. Tests included erosion, corrosion, vibration and fatigue. The results of the …

This project focused on the N and C natural stable isotope response during SOFeX--a purposeful iron (Fe) addition experiment in the Fe limited Southern Ocean. One purpose of the study was to determine if relief of phytoplankton Fe stress would increase productivity sufficiently to enhance C export from surface to deep waters. We proposed that N and C stable isotopes would be useful for tracing this export. Iron was added to waters north and south of the Antarctic Polar Front in waters to the southwest of New Zealand. While both sites have high-nutrient, low chlorophyll conditions (HNLC) typical of Fe limitation, [SiO4] a required nutrient for diatoms was low at the northerly site and high at the southern location. The most extensive coverage occurred at the southern site. Here, FeSO4 was added four different times over an {approx}two week period. We found that: (1) Particulate organic nitrogen and carbon in the mixed layer increased by a factor of 2-3 in response to the Fe addition in the southern patch. (2) PN accumulation and NO3- drawdown were both 1-2 {micro}M during the occupation of the bloom, suggesting retention of particulates within the mixed layer of the southern patch. (3) {sub 15}N …

Palynological results from Julietta Lake currently provide the most direct evidence to support the existence of a glacial refugium for Pinus pumila in mountains of southwestern Beringia. Both percentages and accumulation rates indicate the evergreen shrub survived until at least {approx}19,000 14C yr B.P. in the Upper Kolyma region. Percentage data suggest numbers dwindled into the late glaciation, whereas pollen accumulation rates point towards a more rapid demise shortly after {approx}19,000 14C yr B.P. Pinus pumila did not re-establish in any great numbers until {approx}8100 14C yr B.P., despite the local presence {approx}9800 14C yr B.P. of Larix dahurica, which shares similar summer temperature requirements. The postglacial thermal maximum (in Beringia {approx}11,000-9000 14C yr B.P.) provided Pinus pumila shrubs with equally harsh albeit different conditions for survival than those present during the LGM. Regional records indicate that in this time of maximum warmth Pinus pumila likely sheltered in a second, lower-elevation refugium. Paleoclimatic models and modern ecology suggest that shifts in the nature of seasonal transitions and not only seasonal extremes have played important roles in the history of Pinus pumila over the last {approx}21,000 14C yr B.P.

The following are proposed activities for quarter 2 (9/15/00-12/14/00): (1) Conduct TGA and fuel characterization studies--Task 1; (2) Perform re-burn experiments--Task 2; (3) Fabricate fixed bed gasifier/combustor--Task 3; and (4) Modify the 3D combustion modeling code for feedlot and litter fuels--Task 4. The following were achieved During Quarter 2 (9/15/00-12/14/00): (1) The chicken litter has been obtained from Sanderson farms in Denton, after being treated with a cyclonic dryer. The litter was then placed into steel barrels and shipped to California to be pulverized in preparation for firing. Litter samples have also been sent for ultimate/proximate laboratory analyses.--Task 1; (2) Reburn-experiments have been conducted on coal, as a base case for comparison to litter biomass. Results will be reported along with litter biomass as reburn fuel in the next report--Task 2; (3) Student has not yet been hired to perform task 3. Plans are ahead to hire him or her during quarter No. 3; and (4) Conducted a general mixture fraction model for possible incorporation in the code.

The effect of the application of a DC current on the annealing of point defects in Ni{sub 3}Ti was investigated by positron annihilation spectroscopy (PAS). An increased rate of point defect annealing is observed under the influence of a current and is attributed to a 24% decrease in the mobility activation energy. The results are interpreted in terms of the electron wind effect and the complex nature of diffusion in ordered intermetallic phases. This work represents the first direct evidence of the role of the current on the mobility of point defects in intermetallic systems.

Presentation on renewable energy innovations and policies by Dr. Dan Arvizu of the National Renewable Energy Laboratory.

Presentation on renewable energy innovations and policies by Dr. Dan Arvizu of the National Renewable Energy Laboratory.

Fermilab has long had the world's most intense antiproton source. Despite this, the opportunities for medium-energy antiproton physics at Fermilab have been limited in the past and - with the antiproton source now exclusively dedicated to serving the needs of the Tevatron Collider - are currently nonexistent. The anticipated shutdown of the Tevatron in 2010 presents the opportunity for a world-leading medium-energy antiproton program. We summarize the current status of the Fermilab antiproton facility and review some physics topics for which the experiment we propose could make the world's best measurements. Among these, the ones with the clearest potential for high impact and visibility are in the area of charm mixing and CP violation. Continued running of the Antiproton Source following the shutdown of the Tevatron is thus one of the simplest ways that Fermilab can restore a degree of breadth to its future research program. The impact on the rest of the program will be minor. We request a small amount of effort over the coming months in order to assess these issues in more detail.

We report on the evolution of defects in Pu during isochronal annealing and self irradiation using positron annihilation spectroscopy. Positron annihilation spectroscopy is a sensitive probe (part per million level) for atomic-scale defects. The spectroscopic tools available at LLNL allow the determination of size, concentration, and chemical surroundings of defects in aged Pu samples. Positron lifetime analysis was performed on eight samples aged 7 months to 42 years. All samples except the 7-month old sample contained a high concentration of positron trapping centers. The dominant component yielded a lifetime value of {approx}182 ps. In aged samples, a second longer lifetime component was observed that appears to increase in strength with the age of the sample. The observed lifetime values and their relative strengths are shown in figure 1. The top panel corresponds to the lifetime values and the bottom panel corresponds to the intensity of the long lifetime component. Positron lifetime values are determined by the bubble size and He content. When He is added to a bubble, the positron lifetime is shortened due to the increased electron density. When the size of the bubble is known from an independent measurement, the observed positron lifetime values and the associated first …

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.

Hydrogen embrittlement of 304 stainless steel with different hydrogen concentrations has been investigated. An electrochemical technique was used to effectively charge the high level of hydrogen into 304 stainless steel in a short period of time. At 25 ppm of hydrogen, 304 stainless steel loses 10 percent of its original mechanical strength and 20 percent plasticity. Although the ductile feature dominates the fractography, the brittle crown area near the outer surface shows the intergranular rupture effected by hydrogen. At 60 ppm of hydrogen, 304 stainless steel loses 23 percent of its strength and 38 percent plasticity, where the brittle mode dominates the fracture of the materials. Experimental results show that hydrogen damage to the performance of 304 stainless steel is significant even at very low levels. The fractograph analysis indicates the high penetration ability of hydrogen in 304 stainless steel. This work also demonstrates the advantages of the electrochemical charging technique in the study of hydrogen embrittlement.

Adaptive optics (AO), a mature technology developed for astronomy to compensate for the effects of atmospheric turbulence, can also be used to correct the aberrations of the eye. The classic phoropter is used by ophthalmologists and optometrists to estimate and correct the lower-order aberrations of the eye, defocus and astigmatism, in order to derive a vision correction prescription for their patients. An adaptive optics phoropter measures and corrects the aberrations in the human eye using adaptive optics techniques, which are capable of dealing with both the standard low-order aberrations and higher-order aberrations, including coma and spherical aberration. High-order aberrations have been shown to degrade visual performance for clinical subjects in initial investigations. An adaptive optics phoropter has been designed and constructed based on a Shack-Hartmann sensor to measure the aberrations of the eye, and a liquid crystal spatial light modulator to compensate for them. This system should produce near diffraction-limited optical image quality at the retina, which will enable investigation of the psychophysical limits of human vision. This paper describes the characterization and operation of the AO phoropter with results from human subject testing.

This final report includes details on the research accomplished by the grant entitled 'Exploitation of Parallelism in Climate Models' to the University of Maryland. The purpose of the grant was to shed light on (a) how to reconfigure the atmospheric prediction equations such that the time iteration process could be compressed by use of MPP architecture; (b) how to develop local subgrid scale models which can provide time and space dependent parameterization for a state-of-the-art climate model to minimize the scale resolution necessary for a climate model, and to utilize MPP capability to simultaneously integrate those subgrid models and their statistics; and (c) how to capitalize on the MPP architecture to study the inherent ensemble nature of the climate problem. In the process of addressing these issues, we created parallel algorithms with spectral accuracy; we developed a process for concurrent climate simulations; we established suitable model reconstructions to speed up computation; we identified and tested optimum realization statistics; we undertook a number of parameterization studies to better understand model physics; and we studied the impact of subgrid scale motions and their parameterization in atmospheric models.

At the request of the Defense Logistics Agency, the Oak Ridge Institute for Science and Education conducted radiological scoping surveys of the Scotia Depot during the period of September 24 through 27, 2007. The scoping survey included visual inspections and limited radiological surveys performed in accordance with area classification that included surface scans, total and removable activity measurements, and soil sampling.

The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry. This goal of this project is to develop two types of dense ceramic membrane for producing hydrogen nongalvanically, i.e., without electrodes or external power supply, at commercially significant fluxes under industrially relevant operating conditions. The first type of membrane, hydrogen transport membranes (HTMs), will be used to separate hydrogen from gas mixtures such as the product streams from coal gasification, methane partial oxidation, and water-gas shift reactions. Potential ancillary uses of HTMs include dehydrogenation and olefin production, as well as hydrogen recovery in petroleum refineries and ammonia synthesis plants, the largest current users of deliberately produced hydrogen. The second type of membrane, oxygen transport membranes (OTMs), will produce hydrogen by nongalvanically removing oxygen that is generated when water dissociates at elevated temperatures. This report describes progress that was made during FY 2006 on the development of OTM and HTM materials.

This report details the chemical and radionuclide contaminant results for the characterization of the 2012 Fourth Quarter sampling of Tank 50 for the Saltstone Waste Acceptance Criteria (WAC).Information from this characterization will be used by Waste Solidification Engineering (WSE) to support the transfer of low-level aqueous waste from Tank 50 to the Salt Feed Tank in the Saltstone Facility in Z-Area, where the waste will be immobilized. This information is also used to update the Tank 50 Waste Characterization System. The following conclusions are drawn from the analytical results provided in this report: The concentration of the reported chemical and radioactive contaminants were less than their respective WAC Limits and Targets, unless noted in this section; Norpar 13 and Isopar L have higher detection limits compared with the Saltstone WAC. The data provided in this report is based upon the concentrations in the sub-sample, and due to the limited solubility in aqueous solution, may not represent the concentrations of the analytes in Tank 50; Diisooctyl adipate (or diisooctyl hexanedioate) and 5-methyl-3-hexanol, plasticizers, were measured at 1.30E+00 mg/L and 3.00E+00 mg/L, respectively, in one of two replicate measurements conducted on an at-depth sample. The organic analysis of the at-depth sample was …

An unplanned release of tritiated water occurred at K reactor on SRS between 22-December and 25-December 1991. This water moved down through the effluent canal, Pen Branch, Steel Creek and finally to the Savannah River. Samples were collected in the Savannah River and associated waterways over a period of a month. The Environmental Technology Section (ETS) of the Savannah River Laboratory performed liquid scintillation analyses to monitor the passage of the tritiated water from SRS to the Atlantic Ocean.

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The Hanford Tanks Initiative was established in 1996 to address a range of retrieval and closure issues associated with radioactive and hazardous waste stored in Hanford`s single shell tanks (SSTs). One of HTI`s retrieval goals is to ``Successfully demonstrate technology(s) that provide expanded capabilities beyond past practice sluicing and are extensible to retrieve waste from other SSTS.`` Specifically, HTI is to address ``Alternative technologies to past practice sluicing`` ... that can ... ``successfully remove the hard heel from a sluiced tank or to remove waste from a leaking SST`` (HTI Mission Analysis). During fiscal year 1997, the project contracted with seven commercial vendor teams to demonstrate retrieval technologies using waste simulants. These tests were conducted in two series: three integrated tests (IT) were completed in January 1997, and four more comprehensive Alternative Technology Retrieval Demonstrations (ARTD) were completed in July 1997. The goal of this testing was to address issues to minimize the risk, uncertainties, and ultimately the overall cost of removing waste from the SSTS. Retrieval technologies can be separated into three tracks based on how the tools would be deployed in the tank: globally (e.g., sluicing) or using vehicles or robotic manipulators. Accordingly, the HTI tests included an …

This document summarizes existing criticality safety evaluations and identifies design features that are considered to be one of the two contingencies required to prevent exceeding the criticality limit of 0.95 k eff in the Plutonium Finishing Plant.

Localization of targets imbedded in a heterogeneous background medium is a common problem in seismic, ultrasonic, and electromagnetic imaging problems. The best imaging techniques make direct use of the eigenfunctions and eigenvalues of the array response matrix, as recent work on time-reversal acoustics has shown. Of the various imaging functionals studied, one that is representative of a preferred class is a time-domain generalization of MUSIC (MUltiple Signal Classification), which is a well-known linear subspace method normally applied only in the frequency domain. Since statistical stability is not characteristic of the frequency domain, a transform back to the time domain after first diagonalizing the array data in the frequency domain takes optimum advantage of both the time-domain stability and the frequency-domain orthogonality of the relevant eigenfunctions.