The local structure of aqueous metal ions on solid surfaces is central to understanding many chemical and biological processes in soil and aquatic environments. Here, the local coordination structure of hydrated Zn(II) at water-TiO{sub 2} interfaces was identified by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations. A nonintegral coordination number of average {approx}4.5 O atoms around a central Zn atom was obtained by EXAFS analysis. DFT calculations indicated that this coordination structure was consistent with the mixture of 4-coordinated bidentate binuclear (BB) and 5-coordinated bidentate mononuclear (BM) metastable equilibrium adsorption (MEA) states. The BB complex has 4-coordinated Zn, while the monodentate mononuclear (MM) complex has 6-coordinated Zn, and a 5-coordinated adsorbed Zn was found in the BM adsorption mode. DFT calculated energies showed that the lower-coordinated BB and BM modes were thermodynamically more favorable than the higher-coordinated MM MEA state. The experimentally observed XANES fingerprinting provided additional direct spectral evidence of 4- and 5-coordinated Zn-O modes. The overall spectral and computational evidence indicated that Zn(II) can occur in 4-, 5-, and 6-oxygen coordinated sites in different MEA states due to steric hindrance effects, and the coexistence of …

In the second paper of this series, we evaluate two additional well designs for production from permafrost-associated (PA) hydrate deposits. Both designs are within the capabilities of conventional technology. We determine that large volumes of gas can be produced at high rates (several MMSCFD) for long times using either well design. The production approach involves initial fluid withdrawal from the water zone underneath the hydrate-bearing layer (HBL). The production process follows a cyclical pattern, with each cycle composed of two stages: a long stage (months to years) of increasing gas production and decreasing water production, and a short stage (days to weeks) that involves destruction of the secondary hydrate (mainly through warm water injection) that evolves during the first stage, and is followed by a reduction in the fluid withdrawal rate. A well configuration with completion throughout the HBL leads to high production rates, but also the creation of a secondary hydrate barrier around the well that needs to be destroyed regularly by water injection. However, a configuration that initially involves heating of the outer surface of the wellbore and later continuous injection of warm water at low rates (Case C) appears to deliver optimum performance over the period it …

The objective of this paper is to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsaturated zone and riverbed clogging. We quantify river clogging by calibrating a time-dependent riverbed permeability function based on knowledge of pumping rate, river stage, and temperature. The dynamics of the estimated riverbed permeability reflects clogging and scouring mechanisms. Our results indicate that (1) riverbed permeability is the dominant factor affecting infiltration needed for sustainable RBF production; (2) dam operation can influence pumping efficiency and prevent the development of an unsaturated zone beneath the riverbed only under conditions of sufficient riverbed permeability; (3) slow river velocity, caused by dam raising during summer months, may lead to sedimentation and deposition of fine-grained material within the riverbed, which may clog the riverbed, limiting recharge to the collector wells and contributing to the development of an unsaturated zone …

A high-pressure atomic force microscope (AFM) that enables in situ, atomic scale measurements of topography of solid surfaces in contact with supercritical CO{sub 2} (scCO{sub 2}) fluids has been developed. This apparatus overcomes the pressure limitations of the hydrothermal AFM and is designed to handle pressures up to 100 atm at temperatures up to ∼350 K. A standard optically-based cantilever deflection detection system was chosen. When imaging in compressible supercritical fluids such as scCO{sub 2} , precise control of pressure and temperature in the fluid cell is the primary technical challenge. Noise levels and imaging resolution depend on minimization of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in situ atomic scale imaging of a calcite (CaCO{sub 3}) mineral surface in scCO{sub 2}; both single, monatomic steps and dynamic processes occurring on the (10{overbar 1}4) surface are presented. This new AFM provides unprecedented in situ access to interfacial phenomena at solid–fluid interfaces under pressure.

A preserved sample of hydrate-bearing sandstone from the Mount Elbert Test Well was dissociated by depressurization while monitoring the internal temperature of the sample in two locations and the density changes at high spatial resolution using x-ray CT scanning. The sample contained two distinct regions having different porosity and grain size distributions. The hydrate dissociation occurred initially throughout the sample as a result of depressing the pressure below the stability pressure. This initial stage reduced the temperature to the equilibrium point, which was maintained above the ice point. After that, dissociation occurred from the outside in as a result of heat transfer from the controlled temperature bath surrounding the pressure vessel. Numerical modeling of the test using TOUGH+HYDRATE yielded a gas production curve that closely matches the experimentally measured curve.

The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

This report summarizes the special analysis (SA) of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 1) demonstrating the before and after impacts of the waste stream to the DOE Order 435.1 performance objective at the disposal facility, and the peak dose. The Nevada Division of Environmental Protection (NDEP) requested this SA and asked the Nevada Site Office (NSO) to run the SA deterministically and assume that all the model conditions remain the same regardless of the length of time to the peak dose. Although the NDEP accepts that DOE Order 435.1 requires a compliance period of 1,000 years, it also requested to know what year, if any, the specific DOE performance objectives will be exceeded. Given the NDEP’s requested model conditions, the SA demonstrates the Rn-222 peak dose will occur in about 2 million years and will exceed the performance objective in about 6,000 years. The 0.25 mSv y-1 all-pathway performance objective was not exceeded for the resident scenario after reaching the 4 million year peak dose.

Correspondence issued by the Government Accountability Office with an abstract that begins "Al Qaeda, the Taliban, and other extremists have used safe havens along Pakistan's Western Frontier (border) region to attack Pakistani, Afghan, U.S., and coalition troops; plan and train for attacks against U.S. interests and the U.S. homeland; destabilize Pakistan, a nuclear-armed U.S. ally; and spread radical Islamic ideologies that threaten U.S. interests. A key U.S. national security objective is to disrupt, dismantle, and defeat al Qaeda and its violent extremist affiliates in Pakistan and to deny them a safe haven. Since 2002, the United States has provided over $18 billion in assistance and reimbursement to Pakistan including (1) reimbursements to the Pakistani government for costs incurred in direct support of U.S. counterterrorism operations; (2) security assistance such as grants to Pakistan for the acquisition of military equipment; and (3) development, economic, and humanitarian assistance. Since 2006, this assistance has included $1.5 billion to improve the counterterrorism and counterinsurgency capabilities of Pakistani security forces operating along the country's border with Afghanistan, including $400 million for the Pakistan Counterinsurgency Fund (PCF) and $700 million for the Pakistan Counterinsurgency Capabilities Fund (PCCF). The President has requested an additional $1.2 billion for …

Testimony issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security (DHS) reports that the nearly 2,000-mile U.S. border with Mexico is vulnerable to cross-border illegal activity. The Office of Border Patrol (Border Patrol), within DHS's U.S. Customs and Border Protection (CBP), is responsible for securing the border between U.S. ports of entry and has divided responsibility for southwest border miles among nine Border Patrol sectors. CBP reported spending about $3 billion on Border Patrol's southwest border efforts in fiscal year 2010, apprehending over 445,000 illegal entries. This testimony provides preliminary observations on (1) the extent to which DHS reported progress in achieving operational control--Border Patrol was able to detect, respond, and interdict cross-border illegal activity--of the southwest border; (2) the extent to which operational control reflects Border Patrol's ability to respond to illegal activity at the border or after entry into the United States; and (3) how DHS reports the transition to new border security measures will change oversight and resource requirements for securing the southwest border. This testimony is based on GAO's ongoing work for the House Committee on Homeland Security. GAO analyzed DHS border security documents and data supporting border security …

As a result of soaring energy demand from a staggering pace of economic expansion and the related growth of energy-intensive industry, China overtook the United States to become the world's largest contributor to CO{sub 2} emissions in 2007. At the same time, China has taken serious actions to reduce its energy and carbon intensity by setting both a short-term energy intensity reduction goal for 2006 to 2010 as well as a long-term carbon intensity reduction goal for 2020. This study presents a China Energy Outlook through 2050 that assesses the role of energy efficiency policies in transitioning China to a lower emission trajectory and meeting its intensity reduction goals. Over the past few years, LBNL has established and significantly enhanced its China End-Use Energy Model which is based on the diffusion of end-use technologies and other physical drivers of energy demand. This model presents an important new approach for helping understand China's complex and dynamic drivers of energy consumption and implications of energy efficiency policies through scenario analysis. A baseline ('Continued Improvement Scenario') and an alternative energy efficiency scenario ('Accelerated Improvement Scenario') have been developed to assess the impact of actions already taken by the Chinese government as well as …

A letter report issued by the Government Accountability Office with an abstract that begins "Carbon offsets are reductions in greenhouse gas emissions in one place to compensate for emissions elsewhere. Examples of offset projects include planting trees, developing renewable energy sources, or capturing emissions from landfills. Recent congressional proposals would have limited emissions from utilities, industries, or other "regulated entities," and allowed these entities to buy offsets. Research suggests that offsets can significantly lower the cost of a program to limit emissions because buying offsets may cost regulated entities less than making the reductions themselves. Some existing international and U.S. regional programs allow offsets to be used for compliance with emissions limits. A number of voluntary offset programs also exist, where buyers do not face legal requirements but may buy offsets for other reasons. Prior GAO work found that it can be difficult to ensure offset quality--that offsets achieve intended reductions. One quality criterion is that reductions must be "additional" to what would have occurred without the offset program. This report provides information on (1) key challenges in assessing the quality of different types of offsets and (2) options for addressing key challenges associated with offset quality if the U.S. …

This report describes short-term compensation (STC) as a beneficial alternative to layoffs. It also describes the status of STC (or work sharing) in the U.S., particularly as it varies from state to state.

Crosswell CASSM (continuous active-source seismic monitoring) data was acquired as part of the Frio-II brine pilot CO{sub 2} injection experiment. To gain insight into the CO{sub 2} plume evolution, we have integrated the 3D multiphase flow modeling code TOUGH2 with seismic simulation codes via a petrophysical model that predicts seismic velocity for a given CO{sub 2} saturation. Results of forward seismic modeling based on the CO{sub 2} saturation distribution produced by an initial TOUGH2 model compare poorly with the CASSM data, indicating that the initial flow model did not capture the actual CO{sub 2} plume dynamics. Updates to the TOUGH2 model required to better match the CASSM field data indicate vertical flow near the injection well, with increased horizontal plume growth occurring at the top of the reservoir sand. The CASSM continuous delay time data are ideal for constraining the modeled spatiotemporal evolution of the CO{sub 2} plume and allow improvement in reservoir model and estimation of CO{sub 2} plume properties.

The magnetotelluric method employs co-located surface measurements of electric and magnetic fields to infer the local electrical structure of the earth. The frequency-dependent 'apparent resistivity' curves can be inaccurate at long periods if input data are contaminated - even when robust remote reference techniques are employed. Data despiking prior to processing can result in significantly more reliable estimates of long period apparent resistivities. This paper outlines a two-step method of automatic identification and replacement for spike-like contamination of magnetotelluric data; based on the simultaneity of natural electric and magnetic field variations at distant sites. This simultaneity is exploited both to identify windows in time when the array data are compromised, and to generate synthetic data that replace observed transient noise spikes. In the first step, windows in data time series containing spikes are identified via intersite comparison of channel 'activity' - such as the variance of differenced data within each window. In the second step, plausible data for replacement of flagged windows is calculated by Wiener filtering coincident data in clean channels. The Wiener filters - which express the time-domain relationship between various array channels - are computed using an uncontaminated segment of array training data. Examples are shown where …

This research will focus on characterizing the phase behavior of polyelectrolyte-surfactant microemulsions (PSM) that were recently discovered in our lab and indentifing possible uses of their long-range ordered nanostructures towards bioseparation, oil-recovery and drug delivery systems. In addition, we are proposing strategies for synthesizing solid and long-range ordered materials with unit cells on the nanometer scale using polymerization and/or cross-linking to solidify the soft template.

To evaluate the efficacy of bioimmobilization of Cr(VI) in groundwater at the Department of Energy Hanford site, we conducted a series of microcosm experiments using a range of commercial electron donors with varying degrees of lactate polymerization (polylactate). These experiments were conducted using Hanford Formation sediments (coarse sand and gravel) immersed in Hanford groundwater, which were amended with Cr(VI) and several types of lactate-based electron donors (Hydrogen Release Compound, HRC; primer-HRC, pHRC; extended release HRC) and the polylactate-cysteine form (Metal Remediation Compound, MRC). The results showed that polylactate compounds stimulated an increase in bacterial biomass and activity to a greater extent than sodium lactate when applied at equivalent carbon concentrations. At the same time, concentrations of headspace hydrogen and methane increased and correlated with changes in the microbial community structure. Enrichment of Pseudomonas spp. occurred with all lactate additions, and enrichment of sulfate-reducing Desulfosporosinus spp. occurred with almost complete sulfate reduction. The results of these experiments demonstrate that amendment with the pHRC and MRC forms result in effective removal of Cr(VI) from solution most likely by both direct (enzymatic) and indirect (microbially generated reductant) mechanisms.

CT scanners are deployed world-wide to detect explosives in checked and carry-on baggage. Though very similar to single- and dual-energy multi-slice CT scanners used today in medical imaging, some recently developed explosives detection scanners employ multiple sources and detector arrays to eliminate mechanical rotation of a gantry, photon counting detectors for spectral imaging, and limited number of views to reduce cost. For each bag scanned, the resulting reconstructed images are first processed by automated threat recognition algorithms to screen for explosives and other threats. Human operators review the images only when these automated algorithms report the presence of possible threats. The US Department of Homeland Security (DHS) has requirements for future scanners that include dealing with a larger number of threats, higher probability of detection, lower false alarm rates and lower operating costs. One tactic that DHS is pursuing to achieve these requirements is to augment the capabilities of the established security vendors with third-party algorithm developers. A third-party in this context refers to academics and companies other than the established vendors. DHS is particularly interested in exploring the model that has been used very successfully by the medical imaging industry, in which university researchers develop algorithms that are eventually …

The US Department of Homeland Security (DHS) has requirements for future explosive detection scanners that include dealing with a larger number of threats, higher probability of detection, lower false alarm rates and lower operating costs. One tactic that DHS is pursuing to achieve these requirements is to augment the capabilities of the established security vendors with third-party algorithm developers. The purposes of this presentation are to review DHS's objectives for involving third parties in the development of advanced algorithms and then to discuss how these objectives are achieved using workshops and grand challenges. Terrorists are still trying and they are getting more sophisticated. There is a need to increase the number of smart people working on homeland security. Augmenting capabilities and capacities of system vendors with third-parties is one tactic. Third parties can be accessed via workshops and grand challenges. Successes have been achieved to date. There are issues that need to be resolved to further increase third party involvement.

Testimony issued by the Government Accountability Office with an abstract that begins "Many federal programs and initiatives involve shared responsibilities--and benefits--for the federal, state, local and tribal governments, and the private sector. Federal statutes and rules often require nonfederal parties to expend their resources in support of certain national goals. The Unfunded Mandates Reform Act of 1995 (UMRA) was enacted to address some of the concerns about federal statutes and regulations that require nonfederal parties to expend resources to achieve these goals without being provided funding to cover the costs. UMRA generates information about how these potential federal mandates could affect other levels of government and the private sector as Congress and agency decision makers consider proposed legislation and regulations. Congress has asked GAO to evaluate the effectiveness of UMRA procedures and requirements several times since it was enacted. Based on that body of work, this testimony focuses on Title II of UMRA regarding federal mandates in rules and (1) describes the exceptions and exclusions in the act when identifying a federal mandate and (2) summarizes GAO findings on UMRA's implementation over the years and views of knowledgeable parties on potential improvements. GAO is not making recommendations in this testimony."

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii.

This report addresses foreign aid reform through early 2011. Several development proponents, nongovernmental organizations (NGOs), and policymakers have pressed Congress to reform U.S. foreign aid capabilities to better address 21st century development needs and national security challenges. Foreign aid reform may continue to be a concern in the 112th Congress.

This report focuses on the annual defense authorization process. It includes discussions of pay raises, insurance, social programs, and other personnel policy issues.

The valence fluctuation compounds are rare earth intermetallics where hybridization of the nearly-localized 4f electrons with the conduction electrons leads to incorporation of the 4f's into the itinerant states. This hybridization slows down the conduction electrons and hence gives them a heavy effective mass, justifying application of the term 'heavy Fermion' (HF) to these materials. During the project period, we grew large single crystals of several such compounds and measured their properties using both standard thermodynamic probes and state-of-the-art inelastic neutron scattering. We obtained three main results. For the intermediate valence compounds CePd{sub 3} and YbAl{sub 3}, we showed that the scattering of neutrons by the fluctuations of the 4f magnetic moment does not have the momentum dependence expected for the itinerant heavy mass state; rather, the scattering is more typical of a localized spin fluctuation. We believe that incoherent scattering localizes the excitation. For the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sub 0.065}){sub 2}Ge{sub 2}, which sits at a T = 0 critical point for transformation into an antiferromagnetic (AF) phase, we showed that the scattering from the AF fluctuations does not exhibit any of the divergences that are expected at a phase transition. We speculate that alloy disorder profoundly suppresses …

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