Surface science studies related to tribocharging and charge separation studies were performed on electrostatic beneficiation of coal. In contrast to other cleaning methods, electrostatic beneficiation is a dry cleaning process requiring no water or subsequent drying. Despite these advantages, there is still uncertainty in implementing large scale commercial electrostatic beneficiation of coal. The electronic surface states of coal macerals and minerals are difficult to describe due to their chemical complexity and variability [1]. The efficiency in separation of mineral particles from organic macerals depends upon these surface states. Therefore, to further understand and determine a reason for the bipolar charging observed in coal separation, surface analysis studies using Ultra-violet Photoelectron Spectroscopy (UPS) and X-ray Photoelectron Spectroscopy (XPS) were performed on coal samples and several materials that are used or considered for use in tribocharging. Electrostatic charging is a surface phenomenon, so the electronic surface states of the particles, which are influenced by the environmental conditions, determine both polarity and magnitude of tribocharging. UPS was used to measure the work function of the materials as typically used in ambient air. XPS was used to determine the surface chemistry in the form of contamination and degree of oxidation under the same environmental …

Reactor vessel internal components made of nickel-base alloys are susceptible to environmentally assisted cracking (EAC). A better understanding of the causes and mechanisms of this cracking may permit less conservative estimates of damage accumulation and requirements on inspection intervals. The objective of this work is to evaluate and compare the resistance of Alloys 600 and 690 and their welds, such as Alloys 82, 182, 52, and 152, to EAC in simulated light water reactor environments. The existing crack growth rate (CGR) data for these alloys under cyclic and constant loads have been evaluated to establish the effects of alloy chemistry, cold work, and water chemistry. The experimental fatigue CGRs are compared with CGRs that would be expected in air under the same mechanical loading conditions to obtain a qualitative understanding of the degree and range of conditions for significant environmental enhancement in growth rates. The existing stress corrosion cracking (SCC) data on Alloys 600 and 690 and Alloy 82, 182, and 52 welds have been compiled and analyzed to determine the influence of key parameters on growth rates in simulated PWR and BWR environments. The SCC data for these alloys have been evaluated with correlations developed by Scott and by …

In this study, we address a series of fundamental questions regarding the processes and effectiveness of geologic CO{sub 2} sequestration in saline aquifers. We begin with the broadest: what is the ultimate fate of CO{sub 2} injected into these environments? Once injected, it is immediately subject to two sets of competing processes: migration processes and sequestration processes. In terms of migration, the CO{sub 2} moves by volumetric displacement of formation waters, with which it is largely immiscible; by gravity segregation, which causes the immiscible CO{sub 2} plume to rise owing to its relatively low density; and by viscous fingering, owing to its relatively low viscosity. In terms of sequestration, some fraction of the rising plume will dissolve into formation waters (solubility trapping); some fraction may react with formation minerals to precipitate carbonates (mineral trapping); and the remaining portion eventually reaches the cap rock, where it migrates up-dip, potentially accumulating in local topographic highs (structural trapping). Although this concept of competing migration/sequestration processes is intuitively obvious, identifying those sub-processes that dominate the competition is by no means straightforward. Hence, at present there are large uncertainties associated with the ultimate fate of injected CO{sub 2} (Figure 1). Principal among these: can a …

This paper presents a proposal for modifying the current employee annual evaluation process in SCAD. It purports to simplify that process, primarily by breaking up the resultant document into a set of more or less independent components. It claims to reduce the overall time and effort required from each actor.

Representative, simplified geothermal rock-fluid systems are investigated with a modeling approach to estimate how rock water interactions affect coupled properties related to mechanical stability and permeability improvement through fracturing. First, geochemical modeling is used to determine the evolution of fluid chemistry at temperatures up to 300 C when fluids are in contact with representative rocks of continental origin. Then, a kinetic crack growth model for quartz is used to predict growth rate for subcritical cracks in acidic and basic environments. The predicted growth rate is highly sensitive to temperature and pH in the ranges tested. At present, the model is limited to situations in which quartz controls the mechanical process of interest, such as well bore stability in silica cemented rocks and the opening of quartz filled veins to enhance permeability.

In calculating cosmic-ray exposure ages of meteorites it is generally assumed that the meteoroids were expelled from a shielded position within their parent body and then experienced a single stage exposure before colliding with Earth. The combination of noble gas and radionuclide measurements in several large meteorites, such as Jilin and Bur Ghelaui, have revealed complex exposure histories: i.e. an initial exposure on the surface of an asteroid (or within meter-sized meteoroid), followed by a second exposure as a smaller object. In fact, orbital dynamics calculations predicted that at least 30% of the meteorites arriving on Earth experienced two- or multiple-stage exposure histories [1]. More recently, after the recognition that the Yarkovsky effect plays an important role in delivering meteorites from the asteroid belt to Earth-crossing orbits, it was confirmed that complex exposure histories should be common [2]. Nevertheless, despite the ability to measure a wide range of radionuclides with accelerator mass spectrometry (AMS), only a few meteorites with complex exposure histories have been identified [e.g. 3,4]. The question is whether the relatively paucity of complex exposure histories is real or have we simply overlooked complex-exposure histories. In this work we focus on meteorites with low {sup 3}He/{sup 21}Ne ratios, …

Review and test speeds of various encryption technologies using Entrust Software. Multiple encryption algorithms are included in the product. Algorithms tested were IDEA, CAST, DES, and RC2. Test consisted of taking a 7.7 MB Word document file which included complex graphics and timing encryption, decryption and signing. Encryption is discussed in the GIAC Kickstart section: Information Security: The Big Picture--Part VI.

Interest in the synthesis of semiconductor nanoparticles has been generated by their unusual optical and electronic properties arising from quantum confinement effects. We have synthesized silicon and germanium nanoclusters by reacting Zintl phase precursors with either silicon or germanium tetrachloride in various solvents. Strategies have been investigated to stabilize the surface, including reactions with RLi and MgBrR (R = alkyl). This synthetic method produces group IV nanocrystals with passivated surfaces. These nanoparticle emit over a very large range in the visible region. These particles have been characterized using HRTEM, FTIR, UV-Vis, solid state NMR, and fluorescence. The synthesis and characterization of these nanoclusters will be presented.

We find the annihilation rate of positronium (Ps) within silica sodalite. Positron density and the electronic density seen by positrons are compared with a semi-empirical ''free volume'' model.

N/A

Environmental implications of the Kursk submarine sinking

This report describes a study of water velocity around an extended-length submerged bar screen (ESBS) at John Day Dam. The study was conducted for the U.S. Army Corps of Engineers by AScI Corporation and MEVATEC Corporation in March of 2000. This report was prepared by Pacific Northwest National Laboratory. ESBS are being studied as one method for diverting juvenile migrating fish from the dam's turbine intakes into the gate well and through the juvenile fish bypass channels.

Over the period of the program we systematically varied microstructural features of magnetic thin films in an attempt to better identify the role which each feature plays in determining selected extrinsic magnetic properties. This report summarizes the results.

This user's guide describes Visual Sample Plan (VSP) Version 1.0 and provides instructions for using the software. VSP selects the appropriate number and location of environmental samples to ensure that the results of statistical tests performed to provide input to environmental decisions have the required confidence and performance. VSP Version 1.0 provides sample-size equations or algorithms needed by specific statistical tests appropriate for specific environmental sampling objectives. The easy-to-use program is highly visual and graphic. VSP runs on personal computers with Microsoft Windows operating systems (95, 98, Millenium Edition, 2000, and Windows NT). Designed primarily for project managers and users without expertise in statistics, VSP is applicable to any two-dimensional geographical population to be sampled (e.g., surface soil, a defined layer of subsurface soil, building surfaces, water bodies, and other similar applications) for studies of environmental quality.

The TFA uses a systematic process for developing its annual program that draws from the tanks science and technology development needs expressed by the five DOE tank waste sites. TFA's annual program development process is iterative and involves the following steps: Collection of site needs; Needs analysis; Development of technical responses and initial prioritization; Refinement of the program for the next fiscal year; Formulation of the Corporate Review Budget (CRB); Preparation of Program Execution Guidance (PEG) for the next FY Revision of the Multiyear Program Plan (MYPP). This document describes the outcomes of the first phase of this process, from collection of site needs to the initial prioritization of technical activities. The TFA received site needs in October - December 2000. A total of 170 site needs were received, an increase of 30 over the previous year. The needs were analyzed and integrated, where appropriate. Sixty-six distinct technical responses were drafted and prioritized. In addition, seven strategic tasks were approved to compete for available funding in FY 2002 and FY 2003. Draft technical responses were prepared and provided to the TFA Site Representatives and the TFA User Steering Group (USG) for their review and comment. These responses were discussed at …

This report addresses the feasibility of the laboratory measurements of isotopic ratios for selected trace constituents in irradiated nuclear-grade graphite, based on the results of a proof-of-principal experiment completed at Pacific Northwest National Laboratory (PNNL) in 1994. The estimation of graphite fluence through measurement of isotopic ratio changes in the impurity elements in the nuclear-grade graphite is referred to as the Graphite Isotope Ratio Method (GIRM). Combined with reactor core and fuel information, GIRM measurements can be employed to estimate cumulative materials production in graphite moderated reactors. This report documents the laboratory procedures and results from the initial measurements of irradiated graphite samples. The irradiated graphite samples were obtained from the C Reactor (one of several production reactors at Hanford) and from the French G-2 Reactor located at Marcoule. Analysis of the irradiated graphite samples indicated that replicable measurements of isotope ratios could be obtained from the fluence sensitive elements of Ti, Ca, Sr, and Ba. While these impurity elements are present in the nuclear-grade graphite in very low concentrations, measurement precision was typically on the order of a few tenths of a percent to just over 1 percent. Replicability of the measurements was also very good with measured values …

An interceptive device referred to here as a scraper has been designed and tested for use in a diagnostic device [1]. The scraper will be used to probe a proton beam in order to detect the formation of beam halo [2]. Probing the proton beam exposes the scraper to high heat fluxes on the order of 610 kW/cm{sup 2}. The high-heat flux exposure is cyclic since the beam is probed while in pulsed mode. In order to test the design repetitive high-heat flux testing has been performed on a prototype design of the scraper. This paper describes the design, analysis, and testing of the scraper.

Los Alamos National Laboratory is building room-temperature rf accelerating structures for the Spallation Neutron Source (SNS). These structures, for H{sup -} ions, consist of six 402.5-MHz, 2-MW drift-tube linac (DTL) tanks from 2.5 to 87 MeV followed by four 805-MHz, 4-MW coupled-cavity linac (CCL) modules to 186 MeV. The DTL uses permanent magnet quadrupoles inside the drift tubes arranged in a 6{beta}{lambda} FFODDO lattice with every third drift tube available for diagnostics and steering. The CCL uses a 13{beta}{lambda} FODO electromagnetic quadrupole lattice. Diagnostics and magnets occupy the 2.5{beta}{lambda} spaces between 8-cavity segments. This paper discusses design of the rf cavities and low-power modeling work.

The 6.7 MeV, 100 mA proton beam being produced in the Low Energy Demonstration Accelerator (LEDA) RFQ is being injected into a 52 magnet lattice in order to study the charged-beam phenomenon known as beam halo [1]. Quadrupole magnets in the lattice are purposely mismatched to cause or amplify halo formation in the beam. Interceptive diagnostics that consist of a thin wire and a paddle type device called a scraper are placed in the beam to obtain charge-distribution data. The charge-distribution data is used to create a current-density distribution plot of the beam at the probed location [2]. This paper describes the mechanical design, fabrication, and commissioning of the interceptive diagnostic devices and the assembly that carries them.

The projects described in this report represent the Laboratory's investment in its future and are vital to maintaining the ability to develop creative solutions for the scientific and technical challenges faced by DOE and the nation. In accordance with DOE guidelines, the report provides, a) a director's statement, b) an overview of the laboratory's LDRD program, including PNNL's management process and a self-assessment of the program, c) a five-year project funding table, and d) project summaries for each LDRD project.

Los Alamos National Laboratory has two identical shufflers that have been calibrated with a dozen U{sub 3}O{sub 8} certified standards from 10 g {sup 235}U to 3600 g {sup 235}U. The shufflers are used to assay a wide variety of material types for their {sup 235}U contents. When the items differ greatly in chemical composition or shape from the U{sub 3}O{sub 8} standards a bias is introduced because the calibration is not appropriate. Recently a new tool has been created to calculate shuffler count rates accurately, and this has been applied to generate bias correction factors. The tool has also been used to verify the masses and count rates of some uncertified U{sub 3}O{sub 8} standards up to 8.0 kg of {sup 235}U which were used to provisionally extend the calibration beyond the 3.6 kg of {sup 235}U mass when a special need arose. Metallic uranium has significantly different neutronic properties from the U{sub 3}O{sub 8} standards and measured count rates from metals are biased low when the U{sub 3}O{sub 8} calibration is applied. The application of the calculational tool to generate bias corrrections for assorted metals will be described. The accuracy of the calculational tool was verified using highly …

N/A

As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall …

This presentation is a series of slides showing the accuracy of hourly data on direct and diffuse irradiance in the central U.S. derived from a satellite.