Measurements of the linewidths of submicrometer features made by different metrology techniques have frequently been characterized by differences of up to 90 nm. The purpose of the work reported here is to address the special difficulties that this phenomenon presents to the certification of reference materials for the calibration of linewidth-measurement instruments. Accordingly, a new test structure has been designed, fabricated, and undergone preliminary tests. Its distinguishing characteristics are assured cross-sectional profile geometries with known side-wall slopes, surface planarity, and compositional uniformity when it is formed in mono-crystalline material at selected orientations to the crystal lattice. To allow the extraction of electrical linewidth, the structure is replicated in a silicon film of uniform conductivity which is separated from the silicon substrate by a buried oxide layer. The utilization of a Silicon-On-Insulator (SKI) substrate further allows the selective removal of substrate material from local regions below the reference features, thus facilitating measurements by optical and electron-beam transmission microscopy. The combination of planar feature surfaces having known side-wall slopes is anticipated to eliminate factors which are believed to be responsible for methods divergence in linewidth measurements, a capability which is a prerequisite for reliable certification of the linewidths of features on reference …

Colloidal transport may increase the amount of contaminant material than that which could be transported by water flow alone. The role of colloids in groundwater contaminant transport is complicated and may involve many different processes, including sorption of elements onto colloidal particles, coagulation/dissolution, adsorption onto solid surfaces, filtration, and migration. Bacteria are known to concentrate minerals and influence the transport of compounds in aqueous environments and may also serve as organic colloids, thereby influencing subsurface transport of radionuclides and other contaminants. The initial phase of the project consisted of assembling a list of bacteria capable of sequestering or facilitating mineral transport. The development and optimization of the PCR amplification assay for the detection of the organisms of interest, and the examination of regional groundwaters for those organisms, are presented for subsequent research.

Analysis of crosswell and three-component seismic data integrated with well logs have produced information on the distribution of subsurface heterogeneities below the In-Tank Precipitation facility at the Savannah River Site (SRS). The travel time P-wave tomogram and reflection imaging delineate lateral and vertical structural details of the formations. In particular, the high-resolution P-wave tomogram captures a low-velocity zone within the carbonates. This zone is surrounded by reflection events between depths of 150 and 200 ft. in the reflection imaging. The reflections are caused by the acoustic impedance contrast between the low velocity zone of `soupy` sand mixtures of unconsolidated materials and the more rigid and dense competent surrounded medium. The time-frequency analysis of full waveforms particle velocity identifies guided waves in form of leaky and normal modes at the depths of about 138 to 150 ft. This resulting change in lithology associated with the presence of guided waves is consistent with a velocity low observed in the vertical velocity profile determined from the inversion of three-component seismic data. This low-velocity zone intercepted by the wells H-BOR-34 and H-BOR-50 correlates with the conductive Griffins Landing Member, which is located above the carbonates. The result of the experiments demonstrate that the present …

Autoignition of isomers of pentane, hexane, and primary reference fuel mixture of n-heptane and iso-octane has been studied experimentally under motored engine conditions and computationally using a detailed chemical kinetic reaction mechanism. Computed and experimental results are compared and used to help understand the chemical factors leading to engine knock in spark-ignited engines. The kinetic model reproduces observed variations in critical compression ratio with fuel molecular size and structure, provides intermediate product species concentrations in good agreement with observations, and gives insights into the kinetic origins of fuel octane sensitivity. Sequential computed engine cycles were found to lead to stable, non-igniting behavior for conditions below a critical compression ratio; to unstable, oscillating but nonigniting behavior in a transition region; and eventually to ignition as the compression ratio is steadily increased. This transition is related to conditions where a negative temperature coefficient of reaction exists, which has a significant influence on octane number and fuel octane sensitivity.

Biologists from Pacific Northwest National Laboratory (PNNL) were requested by personnel from Fort Irwin to conduct a biological reconnaissance of the Avawatz Mountains northeast of Fort Irwin, an area for proposed expansion of the Fort. Surveys of vegetation, small mammals, birds, reptiles, amphibians, and aquatic resources were conducted during 1995 to characterize the populations and habitats present with emphasis on determining the presence of any species of special concern. This report presents a description of the sites sampled, a list of the organisms found and identified, and a discussion of relative abundance. Taxonomic identifications were done to the lowest level possible commensurate with determining the status of the taxa relative to its possible listing as a threatened, endangered, or candidate species. Consultation with taxonomic experts was undertaken for the Coleoptera ahd Hemiptera. In addition to listing the macroinvertebrates found, the authors also present a discussion related to the possible presence of any threatened or endangered species or species of concern found in Sheep Creek Springs, Tin Cabin Springs, and the Amargosa River.

The hydrosilation chemistry involving manganese acyl complexes (L)(CO){sub 4}MnC(O)R (L = CO, PPh{sub 3}; R = CH{sub 3}, Ph) as substrates and as precatalysts has been developed. Results of a kinetics study on the (CO){sub 5}Mn(p-toluoyl)-catalyzed SiH/SiD exchange between DSiMe{sub 2}Ph and HSiMe{sub 2}Et established that coordinatively unsaturated (CO){sub 4}MnSiR{sub 3}, the active catalyst, sequentially adds one substrate silane and then releases a product silane. Results of this mechanistic study afforded the working hypothesis for much of our current research: manganese acyl-hydrosilane mixtures generate unsaturated silyl complexes, which are active catalysts for the hydrosilation of a variety of substrates. These active catalysts, (CO){sub 4}MnSiR{sub 3}, also were generated through photolysis of (CO){sub 5}MnSiR{sub 3}.

Substitution of transition metals for either aluminum and/or phosphorus in the AlPO{sub 4}-11 framework is found to afford novel heterogeneous catalysts for liquid phase hydroxylation of phenol with hydrogen peroxide. AlPO{sub 4}-11 is more active than SAPO-11 and MgAPO-11 for phenol conversion to hydroquinone. The Bronsted acid sites of SAPO-11 and MgAPO-11 may promote the decomposition of hydrogen peroxide to water and oxygen, thus leading to lower phenol conversions. Substitution of divalent and trivalent metal cations, such as Fe, Co and Mn appears to significantly improve the conversion of phenol. The activity follows the order of FeAPO-11>FeMnAPO-11>CoAPO-11>MnAPO-11{much_gt}ALPO{sub 4}-11. FeAPO-11, FeMnAPO-11 and AlPO{sub 4}-11 give similar product selectivities of about 1:1 hydroquitione (HQ) to catechol (CT). MnAPO-11 and CoAPO-11 favor the production of catechol, particularly at low conversions. FeAPO-11 and TS-1 (titanium silicate with MFI topology) are comparable for the phenol conversions with TS-1 giving higher selectivities toward hydroquinone. The external surfaces of the catalysts plays a significant role in these oxidation reactions. MeAPO molecular sieves may be complementary to the metal silicalite catalysts for the catalytic oxidations in the manufacture of fine chemicals.

Vitrification has been identified as a viable choice in the disposition of actinide materials such as americium (Am), curium (Cm), neptunium (Np), and plutonium (Pu). At the Westinghouse Savannah River Company near Aiken, South Carolina, a process is being developed to safely vitrify all of the highly radioactive americium/curium material and a portion of the other fissile actinide materials stored on site. This vitrification will allow safe transportation of the Am/Cm as well as easy storage at their final destination of Oak Ridge National Laboratory. This Am/Cm glass has been designed to be extremely durable in aqueous environments and can be selectively attacked by nitric acid to allow recovery of the valuable Am and Cm isotopes. A similar glass composition could allow for temporary or permanent storage of surplus plutonium. This paper will present results from a durability study on the actinide glass, Am/Cm Target, that will be used to vitrify the americium/curium material. The time, temperature, and compositional dependence of the Am/Cm Target durability will be discussed. All results show that the Am/Cm Target Glass is extremely durable and stable in aqueous systems, which is quite suitable for vitrification of americium/curium and possibly other actinides

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Previous studies demonstrated that Ethemet local area network traffic is statistically self-similar and that the commonly used Poisson models are not able to capture the fractal characteristics of Ethemet traffic. This contribution uses simulated self-similar traffic traces from the MITRE Corporation and Sandia`s simulation software to evaluate the ABR performance of an ATM backbone. The ATM backbone interconnects Ethemet LANs via edge devices such as routers and bridges. We evaluate the overall network performance in terms of throughput, response time, fairness, and buffer requirements. Because typical edge devices perform simple forwarding functions, their usual mechanism for signaling network congestion is packet dropping. Therefore, we believe that the proper provisioning of buffer resources in ATM edge devices is crucial to the overall network performance.

Objectives are to study factors controlling attrition resistance of slurry phase Fe catalysts, synthesize novel precipitated catalysts that overcome some of the limitations of current generation catalysts, and study catalyst-binder interactions using model catalysts. A study of Fe/silica (binder) interactions has been started. Study of effects of Cu on reducibility of Fe catalysts showed that small amounts of Cu can facilitate reduction of Fe{sub 2}O{sub 3} to {alpha}-Fe. Work with Nancy Jackson (Sandia) on carbon deposits in Fe F-T catalysts showed good correlation between peak temperature in TPR and the carbon as seen by TEM. Analyses of samples from Dr. Burtron Davis (U. KY) by XRD and TEM showed that the active catalyst contains small crystallites of iron carbide while the deactivated catalyst had significant transformation into large magnetite crystals. It is felt that improper passivation of these catalysts can lead to mis-identification of the phase in working F-T catalysts.

This five year project is intended to ensure the availability of well- characterized, high-quality coal samples for public and private coal research. It continues support of the DOE Coal Sample Bank and Database at The Pennsylvania State University. Thirty coal samples will be collected, processed, packaged, and analyzed, and a resulting database will be maintained. These samples and data, as well as 26 samples collected under previous contracts, will be distributed to DOE contractors and others performing coal research. Samples will be chosen to maintain a sample bank of 56 coals representing the major US coal fields and a variety of coal ranks and compositions. In addition to standard analyses, liquefaction tests and organic geochemical analyses will be performed. The samples will be stored to minimize deterioration, and will be monitored annually by proximate, sulfur forms, and gaseous oxygen analysis to evaluate their condition. These samples will be used for additional research on the influence of changes in surface chemistry on surface properties, the influence of sample deterioration on liquefaction properties, and the mechanisms of coal oxidation. During the quarter, samples were distributed and inventory records were updated. The newly collected sample was added to the inventory records. One sample …

This report contains the results of a three year study on the preparation of high surface area iron catalysts using a continuous precipitation technique, of a detailed program designed to define the impact of three pretreatment procedures (CO only, syngas only, or hydrogen followed by syngas) on the physical and chemical changes that the catalyst undergoes during activation, and the impact of catalyst composition and pretreatment on the ultimate activity and selectivity of the catalyst during the synthesis. Overall the results of this three year study attained, or came very close to attaining, the activity, aging and selectivity targets in the Statement of Work. This report also contains a critical review of the literature on the preparation of iron catalysts and their pretreatment for use in Fischer-Tropsch synthesis. Also included is a brief review of the action of promoters in Fischer-Tropsch iron catalysts, the models for chemisorption of CO and H{sub 2}, emphasizing that which is appropriate for Fischer-Tropsch synthesis, and an over-view of the results of testing of iron catalysts for Fischer-Tropsch synthesis activity and product selectivity.

This report contains the results of a three year study on the preparation of high surface area iron catalysts using a continuous precipitation technique, of a detailed program designed to define the impact of three pretreatment procedures (CO only, syngas only, or hydrogen followed by syngas) on the physical and chemical changes that the catalyst undergoes during activation, and the impact of catalyst composition and pretreatment on the ultimate activity and selectivity of the catalyst during the synthesis. Overall the results of this three year study attained, or came very close to attaining, the activity, aging and selectivity targets in the Statement of Work. This report also contains a critical review of the literature on the preparation of iron catalysts and their pretreatment for use in Fischer-Tropsch synthesis. Also included is a brief review of the action of promoters in Fischer-Tropsch iron catalysts, the models for chemisorption of CO and H{sub 2}, emphasizing that which is appropriate for Fischer-Tropsch synthesis, and an over-view of the results of testing of iron catalysts for Fischer-Tropsch synthesis activity and product selectivity.

Oak Ridge National Laboratory and Babcock and Wilcox, a prominent U.S. boiler manufacturer, have collaborated under this CRADA to investigate the application of deterministic chaos theory to improve the performance of fossil fuel boilers. The types of boilers investigated were coal-fired fluidized beds and more conventional pulverized coal systems. The results of this investigation demonstrate that chaotic time series analysis of boiler signals (e.g., pressure, acoustic and/or optical signals) can be used to characterize the combustion dynamics with greater accuracy than is possible with conventional signal analysis. Further, it is expected that these new analysis techniques will lead to a new generation of boiler diagnostics and control technology that can make U.S. industry more competitive in the world boiler market. Babcock and Wilcox is initiating follow-on internal and external research to further develop the technology.

This report introduces and evaluates system analysis tools that were developed, or are under development, for the Robotics Technology Development Program (RTDP). Additionally, it discusses system analysis work completed using these tools aimed at completing a system analysis of the retrieval of waste from underground storage tanks on the Hanford Reservation near Richland, Washington. The tools developed and evaluated include a mixture of commercially available tools adapted to RTDP requirements, and some tools developed in house. The tools that are included in this report include: a Process Diagramming Tool, a Cost Modeling Tool, an Amortization Modeling Tool, a graphical simulation linked to the Cost Modeling Tool, a decision assistance tool, and a system thinking tool. Additionally, the importance of performance testing to the RTDP and the results of such testing executed is discussed. Further, the results of the Tank Waste Retrieval (TWR) System Diagram, the TWR Operations Cost Model, and the TWR Amortization Model are presented, and the implication of the results are discussed. Finally, the RTDP system analysis tools are assessed and some recommendations are made regarding continuing development of the tools and process.

An important issue in nuclear waste repository performance is the potential for fracture development resulting in pathways for release of radionuclides beyond the confines of the repository. A series of demonstration calculations using structural finite element analyses are presented here to examine the effect of internal gas generation on the response of a sealed repository. From the calculated stress fields, the most probable location for a fracture to develop was determined to be within the pillars interior to the repository for the range of parameter values considered. If a fracture interconnects the rooms and panels of the repository, fracture opening produces significant additional void volume to limit the excess gas pressure to less than 1.0 MPa above the overburden pressure. Consequently, the potential for additional fracture development into the barrier pillar is greatly reduced, which provides further confidence that the waste will be contained within the repository.

Water hammer event s in steam distribution piping interrupt service and have the potential to cause serious injury and property damage. Conditions of condensation induced water hammer are discussed and recommendations aimed to improve safety of steam systems are presented. Condensate induced water hammer events at Hanford, a DOE facility, are examined.

This work is being carried out as a feasibility study to determine if a long-term course of work can be implemented to assess the long-term risks of radiation exposure delivered at low to moderate dose rates to the populations living in the vicinity of the Mayak Industrial Association (MIA). This work was authorized and conducted under the auspices of the US-Russian Joint Coordinating Committee on Radiation Effects Research (JCCRER) and its Executive Committee (EC). The MIA was the first Russian site for the production and separation of plutonium. This plant began operation in 1948, and during its early days there were technological failures that resulted in the release of large amounts of waste into the rather small Techa River. There were also gaseous releases of radioiodines and other radionuclides during the early days of operation. In addition, there was an accidental explosion in a waste storage tank in 1957 that resulted in a significant release. The Techa River Cohort has been studied for several years by scientists from the Urals Research Centre for Radiation Medicine and an increase in both leukemia and solid tumors has been noted.

The research conducted under this agreement sought to use available satellite data sets to document a variety of climate feedback processes by understanding the mechanisms of current climate variability (seasonal, interannual, temperature dependence). Comparisons with feedback processes operating in the GCM were performed to determine which aspects of the variability serve as the most reliable proxies for decadal climate change. This report focuses on three general areas of progress: upper troposphere water vapor, low cloud optical thickness, and tropical cumulus anvil clouds.

This report describes work performed by Energy Conversion Devices, Inc. (ECD) under a 3-year, cost-shared amorphous silicon (a-Si) research program to develop advanced technologies and to demonstrate stable 14%-efficient, triple-junction a-Si alloy solar cells. The technologies developed under the program will then be incorporated into ECD`s continuous roll-to-roll deposition process to further enhance ECD`s photovoltaic manufacturing technology. In ECD`s solar cell design, triple-junction a-Si alloy solar cells are deposited onto stainless-steel substrates coated with Ag/ZnO back-reflector layers. This type of cell design enabled ECD to use a continuous roll- to-roll deposition process to manufacture a-Si PV materials in high volume at low cost. Using this cell design, ECD previously achieved 13.7% initial solar cell efficiency using the following features: (1) a triple-junction, two-band-gap, spectrum-splitting solar cell design; (2) a microcrystalline silicon p-layer; (3) a band-gap-profiled a- SiGe alloy as the bottom cell i-layer; (4) a high-performance AgZnO back-reflector; and (5) a high-performance tunnel junction between component cells. ECD also applied the technology into its 2-MW/yr a- Si production line and achieved the manufacturing of 4-ft{sup 2} PV modules with 8% stable efficiency. During this program, ECD is also further advancing its existing PV technology toward the goal of 14% stable …

To address the question of the value of auxiliary stations placed before the GSE by the Ad Hoc Committee on Nuclear Test Ban, we examined the published location error estimates given by both the NEIS and the IDC. The results of our analysis demonstrate the well-known principle that the uncertainty in the location for a given event decreases as the number of defining phases (or stations) increases and as the azimuthal coverage increases. More importantly, however, the results also show that the location uncertainty dramatically decreases as the distance to the nearest station decreases. We also show that the empirically observed rate of overlap of corresponding IDC and NEIS error ellipses is inconsistent with expectation as determined by statistically modeling the performance of each. To overcome this shortcoming the IMS must be calibrated.

This document is a draft final report (Volume 1) for US DOE contract entitled, {open_quotes}Demonstration Testing and Evaluation of In Situ Soil Heating,{close_quotes} Contract No. DE-AC05-93OR22160, IITRI Project No. C06787. This report is presented in two volumes. Volume I contains the technical report and Volume II contains appendices with background information and data. In this project approximately 300 cu. yd. of clayey soil containing a low concentration plume of volatile organic chemicals was heated in situ by the application of electrical energy. It was shown that as a result of heating the effective permeability of soil to air flow was increased such that in situ soil vapor extraction could be performed. The initial permeability of soil was so low that the soil gas flow rate was immeasurably small even at high vacuum levels. When scaled up, this process can be used for the environmental clean up and restoration of DOE sites contaminated with VOCs and other organic chemicals boiling up to 120{degrees} to 130{degrees}C in the vadose zone. Although it may applied to many types of soil formations, it is particularly attractive for low permeability clayey soil where conventional in situ venting techniques are limited by low air flow.