Although materials that exhibit nearest-neighbor-only antiferromagnetic interactions and geometrical frustration theoretically should not magnetically order in the absence of disorder, few such systems have been observed experimentally. One such system appears to be the pyrochlore Tb{sub 2}Ti{sub 2}O{sub 7}. However, previous structural studies indicated that Tb{sub 2}Ti{sub 2}O{sub 7} is an imperfect pyrochlore. To clarify the situation, we performed neutron powder diffraction (NPD) and x-ray absorption fine structure (XAFS) measurements on samples that were prepared identically to those that show no magnetic order. The NPD measurements show that the long-range structure of Tb{sub 2}Ti{sub 2}O{sub 7} is well ordered with no structural transitions between 4.5 and 600 K. In particular, mean-squared displacements (u{sup 2}'s) for each site follow a Debye model with no offsets. No evidence for Tb/Ti site interchange was observed within an upper limit of 2%. Likewise, no excess or deficiency in the oxygen stoichiometry was observed, within an upper limit of 2% of the nominal pyrochlore value. Tb L{sub III} and Ti K-edge XAFS measurements from 20-300 K similarly indicate a well-ordered local structure. Other aspects of the structure are considered. We conclude that Tb{sub 2}Ti{sub 2}O{sub 7} has, within experimental error, an ideal, disorder-free pyrochlore lattice, …

We are developing cryogenic bolometers to measure the total energy of the Linac Coherent Light Source (LCLS) free electron X-ray laser that is currently being built at the Stanford Linear Accelerator Center. LCLS will produce ultrashort {approx}200 fs X-ray laser pulses with {approx}10{sup 13} photons at 0.8 keV up to {approx}10{sup 12} photons at 8 keV per pulse at a repeat interval as short as 8 ms, and will be accompanied by a halo of spontaneous undulator radiation. Our bolometer consists of a 375 {micro}m thick Si absorber and a Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} sensor operated at its metal-insulator transition. It will measure the total energy of each pulse with a precision of <1%, and is designed to meet the conflicting requirements of radiation hardness, sensitivity, linearity over a dynamic range of three orders of magnitude, and readout speed compatible with the LCLS pulse rate. Here we discuss bolometer design and fabrication, and the photoresponse of prototype devices to pulsed optical lasers.

One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures.

None

The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture …

This research involves a combined experimental modeling study that builds on our previous DOE-sponsored work in understanding how KMnO4 can be used with in situ cleanups of contaminated sites. The specific objectives of this study are (1) to describe how solid forms of KMnO4 behave in saturated media, (2) to undertake flow tank studies that examine the hydraulic impact of reaction products (especially MnO2) on the flux of water through the zone of contamination, and (3) to represent process understanding in flow and transport models. We have made excellent progress in addressing these issues through a variety of different laboratory and theoretical investigations, as well as work that summarizes the state of the science. In the space available for this report, we can only summarize the key findings of the study. Readers interested in additional details can refer to the papers that are listed at end of this report. There has been significant industrial interest in the use of KMnO4 schemes for the in situ destruction of various chlorinated solvents. Given our previous work that emphasized some of the problems associated with field applications of the method, we were invited to contribute to a special edition of Environmental & Engineering …

Initial- and final-state interactions from gluon exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, as well as nuclear shadowing and antishadowing-leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. The physics of such processes thus require the understanding of QCD at the amplitude level; in particular, the physics of spin requires an understanding of the phase structure of final-state and initial-state interactions, as well as the structure of the basic wavefunctions of hadrons themselves. I also discuss transversity in exclusive channels, including how one can use single-spin asymmetries to determine the relative phases of the timelike baryon form factors, as well as the anomalous physics of the normal-normal spin-spin correlation observed in large-angle proton-proton elastic scattering. As an illustration of the utility of light-front wavefunctions, the transversity distribution of a single electron is computed, as defined from its two-particle QED quantum fluctuations.

Liquid array technology has previously been used to show proof-of-principle of a multiplexed non structural protein serological assay to differentiate foot-and-mouth infected and vaccinated animals. The current multiplexed assay consists of synthetically produced peptide signatures 3A, 3B and 3D and recombinant protein signature 3ABC in combination with four controls. To determine diagnostic specificity of each signature in the multiplex, the assay was evaluated against a naive population (n = 104) and a vaccinated population (n = 94). Subsequently, the multiplexed assay was assessed using a panel of bovine sera generated by the World Reference Laboratory for foot-and-mouth disease in Pirbright, UK. This sera panel has been used to assess the performance of other singleplex ELISA-based non-structural protein antibody assays. The 3ABC signature in the multiplexed assay showed comparative performance to a commercially available non-structural protein 3ABC ELISA (Cedi test{reg_sign}) and additional information pertaining to the relative diagnostic sensitivity of each signature in the multiplex is acquired in one experiment. The encouraging results of the evaluation of the multiplexed assay against a panel of diagnostically relevant samples promotes further assay development and optimization to generate an assay for routine use in foot-and-mouth disease surveillance.

In 2006, a drilling campaign was conducted at the Project Shoal Area (PSA) to provide information for model validation, emplace long-term monitoring wells, and develop baseline geochemistry for long term hydrologic monitoring. Water levels were monitored in the vicinity of the drilling, in the existing wells HC-1 and HC-6, as well as in the newly drilled wells, MV-1, MV-2 and MV-3 and their associated piezometers. Periodic water level measurements were also made in existing wells HC-2, HC-3, HC-4, HC-5 and HC-7. A lithium bromide chemical tracer was added to drilling fluids during the installation of the monitoring and validation (MV) wells and piezometers. The zones of interest were the fractured, jointed and faulted horizons within a granitic body. These horizons generally have moderate hydraulic conductivities. As a result, the wells and their shallower piezometers required strenuous purging and development to remove introduced drilling fluids as evidenced by bromide concentrations. After airlift and surging well development procedures, the wells were pumped continuously until the bromide concentration was less then 1 milligram per liter (mg/L). Water quality samples were collected after the well development was completed. Tritium scans were preformed before other analyses to ensure the absence of high levels of radioactivity. …

The objective of this work was to conduct laboratory and field experiments to determine the sensitivity of low frequency electrical measurements (resistivity and induced polarization) to the processes of corrosion and precipitation that are believed to limit permeable reactive barrier (PRB) performance. The research was divided into four sets of experiments that were each written up and submitted to a peer-reviewed journal: [1] A laboratory experiment to define the controls of aqueous chemistry (electrolyte activity; pH; valence) and total zero valent iron (Fe0) available surface area on the electrical properties of Fe0 columns. [2] A laboratory experiment to determine the impact of corrosion and precipitation on the electrical response of synthetic Fe0 columns as a result of geochemical reactions with NaSO4 and NaCO3 electrolytes. [3] Laboratory experiments on a sequence of cores retrieved from the Kansas City PRB to determine the magnitude of electrical and geochemical changes within a field active PRB after eight years of operation [4] Field-scale cross borehole resistivity and induced polarization monitoring of the Kansas City PRB to evaluate the potential of electrical imaging as a technology for non-invasive, long-term monitoring of indicators of reduced PRB performance This report first summarizes the findings of the four …

Magnesium aryloxides were prepared in a variety of solvents through the reaction of dibutyl magnesium with sterically varied aryl alcohols: 2,6-dimethylphenol (H-DMP), 2,6-diisopropylphenol (H-DIP), and 2,4,6-trichlorophenol (H-TCP). Upon using a sufficiently strong Lewis-basic solvent, the monomeric species Mg(DMP){sub 2}(py){sub 3} (1, py = pyridine), Mg(DIP){sub 2}(THF){sub 3}, (2a, THF = tetrahydrofuran) Mg(TCP){sub 2}(THF){sub 3} (3) were isolated. Each of these complexes possesses a five-coordinate magnesium that adopts a trigonal bipyramidal geometry. In the absence of a Lewis base, the reaction with H-DIP yields a soluble trinuclear complex, [Mg(DIP){sub 2}]{sub 3} (2b). The Mg metal centers in 2b adopt a linear arrangement with a four-coordinate central metal while the outer metal centers are reduced to just three-coordinate. Solution spectroscopic methods suggest that while 2b remains intact, the monomeric species (1, 2a, and 3) are involved in equilibria, which facilitate intermolecular ligand transfer.

The radioactive startup of two new SRS processing facilities, the Actinide Removal Process (ARP) and the Modular Caustic-Side-Solvent-Extraction Unit (MCU) will add two new waste streams to the Defense Waste Processing Facility (DWPF). The ARP will remove actinides from the 5.6 M salt solution resulting in a sludge-like product that is roughly half monosodium titanate (MST) insoluble solids and half sludge insoluble solids. The ARP product will be added to the Sludge Receipt and Adjustment Tank (SRAT) at boiling and dewatered prior to pulling a SRAT receipt sample. The cesium rich MCU stream will be added to the SRAT at boiling after both formic and nitric acid have been added and the SRAT contents concentrated to the appropriate endpoint. A concern was raised by an external hydrogen review panel that the actinide loaded MST could act as a catalyst for hydrogen generation (Mar 15, 2007 report, Recommendation 9). Hydrogen generation, and it's potential to form a flammable mixture in the off-gas, under SRAT and Slurry Mix Evaporator (SME) processing conditions has been a concern since the discovery that noble metals catalyze the decomposition of formic acid. Radiolysis of water also generates hydrogen, but the radiolysis rate is orders of magnitude …

Yucca Mountain has been proposed by the U.S. Department of Energy as the nation’s long-term, permanent geologic repository for spent nuclear fuel or high-level radioactive waste. The potential repository would be located in Yucca Mountain’s unsaturated zone (UZ), which acts as a critical natural barrier delaying arrival of radionuclides to the water table. Since radionuclide transport in groundwater can pose serious threats to human health and the environment, it is important to understand how much and how fast water and radionuclides travel through the UZ to groundwater. The UZ system consists of multiple hydrogeologic units whose hydraulic and geochemical properties exhibit systematic and random spatial variation, or heterogeneity, at multiple scales. Predictions of radionuclide transport under such complicated conditions are uncertain, and the uncertainty complicates decision making and risk analysis. This project aims at using geostatistical and stochastic methods to assess uncertainty of unsaturated flow and radionuclide transport in the UZ at Yucca Mountain. Focus of this study is parameter uncertainty of hydraulic and transport properties of the UZ. The parametric uncertainty arises since limited parameter measurements are unable to deterministically describe spatial variability of the parameters. In this project, matrix porosity, permeability and sorption coefficient of the reactive tracer …

This report covers progress made at Oak Ridge National Laboratory (ORNL) on research and development projects that contribute to the advancement of fossil energy technologies. Projects on the ORNL Fossil Energy Program are supported by the U.S. Department of Energy (DOE) Office of Fossil Energy, the DOE National Energy Technology Laboratory (NETL), the DOE Fossil Energy Clean Coal Technology (CCT) Program, the DOE National Petroleum Technology Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve (SPR). The ORNL Fossil Energy Program research and development activities cover the areas of coal, clean coal technology, gas, petroleum, and support to the SPR. An important part of the Fossil Energy Program is technical management of all activities on the DOE Fossil Energy Advanced Research (AR) Materials Program. The AR Materials Program involves research at other DOE and government laboratories, at universities, and at industrial organizations.

A wide variety of seismic methods covering the spectrum from DC to kilohertz have been employed at one time or the other in geothermal environments. The reasons have varied from exploration for a heat source to attempting to find individual fractures producing hot fluids. For the purposes here we will assume that overall objective of seismic imaging is for siting wells for successful location of permeable pathways (often fracture permeability) that are controlling flow and transport in naturally fractured reservoirs. The application could be for exploration of new resources or for in-fill/step-out drilling in existing fields. In most geothermal environments the challenge has been to separate the ''background'' natural complexity and heterogeneity of the matrix from the fracture/fault heterogeneity controlling the fluid flow. Ideally one not only wants to find the fractures, but the fractures that are controlling the flow of the fluids. Evaluated in this work is current state-of-the-art surface (seismic reflection) and borehole seismic methods (Vertical Seismic Profiling (VSP), Crosswell and Single Well) to locate and quantify geothermal reservoir characteristics. The focus is on active methods; the assumption being that accuracy is needed for successful well siting. Passive methods are useful for exploration and detailed monitoring for in-fill …

Project Gnome was the first nuclear experiment conducted under the U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE), Plowshare Program. The Plowshare Program focused on developing nuclear devices exclusively for peaceful purposes. The intent of the Gnome experiment was to evaluate the effects of a nuclear detonation in a salt medium. Historically, Project Gnome consisted of a single detonation of a nuclear device on December 10, 1961 with the Salado Formation. Since the Gnome detonation, the AEC/DOE has conducted surface restoration, site reconnaissance, and decontamination and decommissioning activities at the site. In addition, annual groundwater sampling is performed under a long-term hydrological monitoring program begun in 1972. Coach, an experiment to be located near the Gnome project, was initially scheduled for 1963. Although construction and rehabilitation were completed for Coach, the experiment was canceled and never executed. Known collectively as Project Gnome-Coach, the site is located approximately 25 miles east of Carlsbad, New Mexico, in Eddy County, and is comprised of nearly 680 acres, of which approximately 60 acres are disturbed from the combined AEC/DOE operations. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies …

Global radiative forcing of nitrate and ammonium aerosols has mostly been estimated from aerosol concentrations calculated at thermodynamic equilibrium or using approximate treatments for their uptake by aerosols. In this study, a more accurate hybrid dynamical approach (DYN) was used to simulate the uptake of nitrate and ammonium by aerosols and the interaction with tropospheric reactive nitrogen chemistry in a three-dimensional global aerosol and chemistry model, IMPACT, which also treats sulfate, sea salt and mineral dust aerosol. 43% of the global annual average nitrate aerosol burden, 0.16 TgN, and 92% of the global annual average ammonium aerosol burden, 0.29 TgN, exist in the fine mode (D<1.25 {micro}m) that scatters most efficiently. Results from an equilibrium calculation differ significantly from those of DYN since the fraction of fine-mode nitrate to total nitrate (gas plus aerosol) is 9.8%, compared to 13% in DYN. Our results suggest that the estimates of aerosol forcing from equilibrium concentrations will be underestimated. We also show that two common approaches used to treat nitrate and ammonium in aerosol in global models, including the first-order gas-to-particle approximation based on uptake coefficients (UPTAKE) and a hybrid method that combines the former with an equilibrium model (HYB), significantly overpredict the …

In order to understand how high performance computing (HPC) programs are developed, a series of experiments, using students in graduate level HPC classes and various research centers, were conducted at various locations in the US. In this report, we discuss this research, give some of the early results of those experiments, and describe a web-based Experiment Manager we are developing that allows us to run studies more easily and consistently at universities and laboratories, allowing us to generate results that more accurately reflect the process of building HPC programs.

With the passing of FY2006 supplemental bill H.R. 4939, Congress will have appropriated a total of about $437 billion for the three military operations initiated since the 9/11 attacks: Operation Enduring Freedom (OEF) covering Afghanistan and other Global War on Terror (GWOT) operations, Operation Noble Eagle (ONE) providing enhanced security at military bases, and Operation Iraqi Freedom (OIF), Iraq. On a monthly basis, the Department of Defense (DOD) spent an average of about $6.4 billion for OIF, $1.3 billion for OEF, and $180 million for enhanced base security in FY2005. Potential oversight issues for Congress include getting estimates of the cost to repair and replae war-worn equipment and of possible offsetting costs to DOD's regular budget because equipment is being fixed or bought earlier than planned. DOD's annual war funding may reach $118 billion in FY2006 if the pending supplemental is enacted.

This report details the total cost of counterterrorism operations in the Global War on Terror (GWOT) since the September 2001 terrorist attacks on the United States. This report also includes descriptions of relevant budgetary legislation.

None

A letter report issued by the General Accounting Office with an abstract that begins "U.S. dairy farmers produced 167.7 billion pounds of unprocessed, raw milk in 2000. Federal and state dairy programs influence the minimum prices paid to farmers for raw milk. These prices are based on how the raw milk is to be used. Minimum prices set for raw milk to be used for making drinking milk (fluid milk) are higher than those for milk used for manufacturing cheese, butter, and other dairy products. About 70 percent of the raw milk produced in the United States is regulated under the U.S. Department of Agriculture's (USDA) federal milk marketing order program. The 1996 farm bill established another pricing program -- the Northeast Interstate Dairy Compact (NEDC) -- which is run by a commission that sets a minimum price for raw milk sold as fluid milk in six New England states. The NEDC works in conjunction with federal and state dairy programs to establish an alternative minimum price for raw milk in the Compact states. When the monthly NEDC minimum price exceeds the federal marketing order or state minimum price, the NEDC price becomes the minimum price. Congress is now considering …

The primary objective of this study was to refine the conceptual groundwater flow model for the 200-West Area and vicinity. This is the second of two reports that combine to cover the 200 Area Plateau, an area that holds the largest inventory of radionuclide and chemical waste on the Hanford Site.

Contaminants have leaked into the vadose zone at the USDOE Hanford reservation. It is important to understand the fate and transport of these contaminants to design remediation strategies and long-term waste management plans at the Hanford reservation. Colloids may play an important role in fate and transport of strongly sorbing contaminants, such as Cs or Pu. This project seeks to improve the basic understanding of colloid and colloid-facilitated transport of contaminants in the vadose zone. The specific objectives addressed are: (1) Determine the structure, composition, and surface charge characteristics of colloidal particles formed under conditions similar to those occurring during leakage of waste typical of Hanford tank supernatants into soils and sediments surrounding the tanks. (2) Characterize the mutual interactions between colloids, contaminant, and soil matrix in batch experiments under various ionic strength and pH conditions. We will investigate the nature of the solid-liquid interactions and the kinetics of the reactions. (3) Evaluate mobility of colloids through soil under different degrees of water saturation and solution chemistry (ionic strength and pH). (4) Determine the potential of colloids to act as carriers to transport the contaminant through the vadose zone and verify the results through comparison with field samples collected under …