N/A

N/A

An idealized geometry corresponding to a premixed flame in stagnation-point flow is used to investigate the effects of catalysis on extending the extinction limits of on adiabatic stretched flames. Specifically, a surface catalytic reaction is assumed to occur on the stagnation plane, thereby augmenting combustion in the bulk gas with a exothermic surface reaction characterized by a reduced activation energy. Assuming the activation energies remain large, an asymptotic analysis of the resulting flame structure yields a formula for the extinction limit as a function of various parameters. In particular, it is demonstrated that the presence of a surface catalyst can extend the burning regime, thus counterbalancing the effects of heat loss and flame stretch that tend to shrink it. The analysis is relevant to small-volume combustors, where the increased surface-to-volume ratio can lead to extinction of the nonadiabatic flame in the absence of a catalyst.

Over the laqt decade, network practitioners have focused on monitoring, measuring, and characterizing traffic in the network to gain insight into building critical network components (from the protocol stack to routers and switches to network interface cards). Recent research shows that additional insight can be obtained by monitoring traffic at the application level (Le,, before application-sent traffic is modulated by the protocol stack) rather than in the network (i-e., after it is modulated by the protocol stack). Consequently, this paper describes a Monitor for Application-Generated Network Traffic (MAGNeT) that captures traffic generated by the application rather than traffic in the network. MAGNeT consists of application programs as well as modifications to the standard Linux kernel. Together, these tools provide the capability of monitoring an application's network behavior and protocol state information in production systems. The use of MAGNeT will enable the research community to construct a library of real traces of application-generated traffic from which researchers can more realistically test network protocol designs and theory. MAGNeT can also be used to verify the correct operation of protocol enhancements and to troubleshoot and tune protocol implementations.

The current trend in constructing high-performance computing systems is to connect a large number of machines via a fast interconnect or a large-scale network such as the Internet, This approach relies on the performance of the interconnect (or Internet) to enable Past, large-scale distributed computing. A detailed understanding of the communication traffic is required in order to optimize the operation of entire system. Network researchers traditionally monitor traffic in the network to gain the insight necessary to optimize network operations. Recent work suggests additional insight can be obtained by also monitoring trafflc at the application level. The Monitor for Application-Generated Network Traffic toolkit (MAGNeT) we describe here monitors application trallic patterns In production systems, thus enabling more highly optimized networks and interconnects for the next generation of high performance computing system. Keywords- monitor, measurement, network protocol, traffic characterization, TCP, MAGNet, traces, application-generated traffic, virtual supercomputing, network-aware applications, computational giids, high-perfomiance computing.

The capability to plot superimposed meshes has been added to MCNP{trademark}. MCNP4C featured a superimposed mesh weight window generator which enabled users to set up geometries without having to subdivide geometric cells for variance reduction. The variance reduction was performed with weight windows on a rectangular or cylindrical mesh superimposed over the physical geometry. Experience with the new capability was favorable but also indicated that a number of enhancements would be very beneficial, particularly a means of visualizing the mesh and its values. The mathematics for plotting the mesh and its values is described here along with a description of other upgrades.

Both for offline searches through large data archives and for onboard computation at the sensor head, there is a growing need for ever-more rapid processing of remote sensing data. For many algorithms of use in remote sensing, the bulk of the processing takes place in an 'inner loop' with a large number of simple operations. For these algorithms, dramatic speedups can often be obtained with specialized hardware. The difficulty and expense of digital design continues to limit applicability of this approach, but the development of new design tools is making this approach more feasible, and some notable successes have been reported. On the other hand, it is often the case that processing can also be accelerated by adopting a more sophisticated algorithm design. Unfortunately, a more sophisticated algorithm is much harder to implement in hardware, so these approaches are often at odds with each other. With careful planning, however, it is sometimes possible to combine software and hardware design in such a way that each complements the other, and the final implementation achieves speedup that would not have been possible with a hardware-only or a software-only solution. We will in particular discuss the co-design of software and hardware to achieve …

An X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities, has been built at the Advanced Light Source. The purpose of this beamline is to address the myriad of problems in Materials Science and Physics that require submicron x-ray beams for structural characterization. Many such problems are found in the general area of thin films and nano-materials. For instance, the ability to characterize the orientation and strain state in individual grains of thin films allows us to measure structural changes at a very local level. These microstructural changes are influenced heavily by such parameters as deposition conditions and subsequent treatment. The accurate measurement of strain gradients at the micron and sub-micron level finds many applications ranging from the strain state under nano-indenters to gradients at crack tips. Undoubtedly many other applications will unfold in the future as we gain experience with the capabilities and limitations of this instrument. We have applied this technique to measure grain orientation and residual stress in single grains of pure Al interconnect lines and preliminary results on post-electromigration test experiments are presented. It is shown that measurements with this instrument can be used to resolve the complete stress tensor (6 components) in a submicron …

New experimental data is presented on some exotic metals that exhibit phase changes at cryogenic temperatures. The types of phase changes that were detected in the specific heat data range from martensitic (diffusion less) transitions to superconducting transitions. In addition, the charge density wave (CDW) state in uranium metal was detected in the specific heat. Specific-heat measurements were made in zero-magnetic field using an apparatus capable of obtaining temperatures as low as 0.4 K. Calibration performed on this apparatus, using a single-crystal copper sample, show its accuracy to be 0.50%, while the resolution was better than 0.1%. Our measurements demonstrate that similar high precision and accurate specific-heat measurements can be obtained on milligram-scale samples. In Chapters 2 and 3, specific-heat measurements are presented for the B2 (CsCl structure) alloy AuZn and for {alpha}-uranium (orthorhombic symmetry). The AuZn alloy exhibits a continuous transition at 64.75 K and an entropy of transition of ({Delta}S{sub tr}) 2.02 J K{sup {minus}1} mol{sup {minus}1}. Calculation of the Debye temperature, by extrapolating of the high temperature phase elastic constants to T = 0 K yields a value of 207 K ({+-}2 K), in favorable agreement with the calorimetric value of 219 K ({+-}0.50 K), despite the …

This annual technical progress report is for part of Task 4 (site evaluation), Task 5 (2D seismic design, acquisition, and processing), and Task 6 (2D seismic reflection, interpretation, and AVO analysis) on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford Site. After the SUBCON midyear review in Albuquerque, NM, it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as a monitoring tool to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. The second deployment is to the Department of Defense (DOD) Charleston Naval Weapons Station Solid Waste Management Unit 12 (SWMU-12), Charleston, SC to further test the technique to detect high concentrations of DNAPL. The Charleston Naval Weapons Station SWMU-12 site was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Naval Facilities Engineering Command Southern Division (NAVFAC) personnel. Based upon the review of existing data and due to the shallow target depth, the project team collected three Vertical Seismic Profiles (VSP) and an experimental P-wave seismic reflection line. After …

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

Weekly Jewish newspaper from Fort Worth, Texas that includes local, state, and national news along with extensive advertising.

Experimental measurements and flow visualization of synthetic jets and similar continuous jets are described. The dimensionless stroke length necessary to form a 2-D synthetic jet is between 5 and 10, with wider-nozzle jets consistently requiring a smaller value. Synthetic jets are wider, slower and have more momentum than similar continuous jets. Synthetic jets are generated using four nozzle widths that vary by a factor of four, and the driving frequency is varied over an order of magnitude. The resultant jets are in the range 13.5 < L{sub o}/h < 80.8 and 695 < Re{sub Uo} < 14700. In spite of the large range of stroke lengths, the near-field behavior of the synthetic jets scales with L{sub o}/h.

We have used selective AlGaAs oxidation, dry-etching, and high-gain semiconductor laser simulation to create new in-plane lasers with interconnecting passive waveguides for use in high-density photonic circuits and future integration of photonics with electronics. Selective oxidation and doping of semiconductor heterostructures have made vertical cavity surface emitting lasers (VCSELs) into the world's most efficient low-power lasers. We apply oxidation technology to improve edge-emitting lasers and photonic-crystal waveguides, making them suitable for monolithic integrated microsystems. Two types of lasers are investigated: (1) a ridge laser with resonant coupling to an output waveguide; (2) a selectively-oxidized laser with a low active volume and potentially sub-milliAmp threshold current. Emphasis is on development of high-performance lasers suited for monolithic integration with photonic circuit elements.

The primary objective of the Vadose Zone Transport Field Study is to obtain hydrologic, geophysical, and geochemical data from controlled field studies to reduce the uncertainty in vadose-zone conceptual models and to facilitate the calibration of numerical models for water flow and contaminant transport through Hanford's heterogeneous vadose zone. A secondary objective is to evaluate advanced, cost-effective characterization methods with the potential to assess changing conditions in the vadose zone, particularly as surrogates of currently undetectable high-risk contaminants. The study is designed to assure the measurement of flow-and-transport properties in the same soil volume, a pre-requisite for developing techniques for extrapolating parameters derived from investigations at clean representative sites to contaminated sites with minimal characterization.

Photosynthesis and respiration are the largest fluxes into and out of the biosphere (Molles 1999). Consequently, small changes in these fluxes can potentially produce large changes in the storage of carbon in the biosphere. Terrestrial carbon fluxes account for more than half of the carbon transferred between the atmosphere and the earth's surface (about 120 GigaTons/year), and current stores of carbon in terrestrial ecosystem are estimated at 2060 GigaTons. Increasing attention is being focused on the role of managing and sequestering carbon in the terrestrial biosphere as a means for addressing global climate change (IGBP, 1998; U.S. Department of Energy, 1999). Terrestrial ecosystems are widely recognized as a major biological scrubber for atmosphereic CO{sub 2} and their ability to finction as such can be increased significantly over the next 25 years through careful manipulation. The potential for terrestrial carbon gains has been the subject of much attention (Dixon et al., 1994; Masera et al. 1997; Cao and Woodward, 1998; DeLucia et al. 1999). In contrast to other strategies for reducing net carbon emissions, terrestrial sequestration has the potential for rapid implementation. Strategies that focus on soil carbon are likely to be effective because in addition to being a storage pool …

The chemical and isotopic ({sup 11}B/{sup 10}B, {sup 87}Sr/{sup 86}Sr, {sup 18}O/{sup 16}O, {sup 2}H/H, {sup 13}C/{sup 12}C, {sup 14}C, {sup 3}He/{sup 3}H) compositions of groundwater from the upper aquifer system of the Salinas Valley in coastal central California were investigated in order to delineate the origin and processes of groundwater contamination in this complex system. The Salinas Valley has a relatively deep, confined ''400-foot'' aquifer, overlain by a ''180-foot'' aquifer, and a shallower perched aquifer, all made up of alluvial sand, gravel, and clay deposits. Groundwater from the aquifers have different {sup 14}C ages; fossil ({sup 14}C = 21.3 pmc) for the 400-foot, and modern ({sup 14}C = 72.2 to 98.2 pmc) for the 180-foot. Fresh groundwater in all aquifers is recharged naturally and artificially and through the Salinas River. The two modes of recharge can be distinguished chemically. We identified several different saline components with distinguishable chemical and isotopic fingerprints. (1) Salt-water intrusion in the northern basin has Cl concentrations up to 1700 mg/l, a Na/Cl ratio <sea water, a marine Br/Cl ratio, a Ca/Cl ratio >seawater, {delta}{sup 11}B between +17 and +38 per mil, and {sup 87}Sr/{sup 86}Sr between 0.7088 and 0.7096. Excess dissolved Ca, relative to …

The Environmental Systems Research (ESR) Program, a part of the Environmental Systems Research and Analysis (ESRA) Program, was implemented to enhance and augment the technical capabilities of the INEEL. Strengthening the Technical capabilities of the INEEL will provide the technical base to serve effectively as the Environmental Management Laboratory for the Office of Environmental Management (EM). This is a progress report for the third year of the ESR Program (FY 2000). A report of activities is presented for the five ESR research investment areas: (1) Transport Aspects of Selective Mass Transport Agents, (2) Chemistry of Environmental Surfaces, (3) Materials Dynamics, (4) Characterization Science, and (5) Computational Simulation of Mechanical and Chemical Systems. In addition to the five technical areas, the report describes activities in the Science and Technology Foundations element of the program, e.g., interfaces between ESR and the EM Science Program (EMSP) and the EM Focus Areas. The five research areas are subdivided into 18 research projects. FY 2000 research in these 18 projects has resulted in more than 50 technical papers that are in print, in press, in review, or in preparation. Additionally, more than 100 presentations were made at professional society meetings nationally and internationally. Work supported …

This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 2000 on the U.S. Department of Energy's Hanford Site, Washington. The most extensive contaminant plumes are tritium, iodine-129, and nitrate, which all had multiple sources and are very mobile in groundwater. Carbon tetrachloride and associated organic constituents form a relatively large plume beneath the central part of the Site. Hexavalent chromium is present in smaller plumes beneath the reactor areas along the river and beneath the central part of the site. Strontium-90 exceeds standards beneath each of the reactor areas, and technetium-99 and uranium are present in the 200 Areas. RCRA groundwater monitoring continued during fiscal year 2000. Vadose zone monitoring, characterization, remediation, and several technical demonstrations were conducted in fiscal year 2000. Soil gas monitoring at the 618-11 burial ground provided a preliminary indication of the location of tritium in the vadose zone and in groundwater. Groundwater modeling efforts focused on 1) identifying and characterizing major uncertainties in the current conceptual model and 2) performing a transient inverse calibration of the existing site-wide model. Specific model applications were conducted in support of the Hanford Site carbon tetrachloride Innovative Treatment Remediation Technology; to support …

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.

This report describes the underlying principles and goals of the Sandia ASCI Verification and Validation Program Validation Metrics Project. It also gives a technical description of two case studies, one in structural dynamics and the other in thermomechanics, that serve to focus the technical work of the project in Fiscal Year 2001.