A letter report issued by the Government Accountability Office with an abstract that begins "The Department of Defense's (DOD) operational dependence on space has placed new and increasing demands on current space systems to meet commanders' needs. DOD's Operationally Responsive Space (ORS) concept is designed to more rapidly satisfy commanders' needs for information and intelligence during ongoing operations. Given the potential for ORS to change how DOD acquires and fields space capabilities to support the warfighter, this report discusses to what extent DOD (1) is developing ORS to support warfighter requirements and (2) has a plan that integrates ORS into existing DOD and intelligence community processes and architecture. GAO reviewed and analyzed ORS planning documents, the ORS concept of operations, and processes for meeting warfighter needs and also interviewed defense and intelligence community officials who are involved with the ORS concept."

A letter report issued by the Government Accountability Office with an abstract that begins "The United States has long provided the Cuban people with alternative sources of news and information. As part of this effort, in December 2006 the International Broadcasting Bureau (IBB) awarded sole-source contracts to two Miami radio and television stations--Radio Mambi and TV Azteca--to provide additional broadcasting options. Additionally, the Office of Cuba Broadcasting (OCB) annually awards millions of dollars in contracts for talent services--writers, reporters, and technical support--needed to produce and broadcast news and entertainment programming. GAO evaluated the processes used to award (1) the Radio Mambi and TV Azteca broadcasting contracts, and (2) talent services contracts. We reviewed contract files and other documentation and interviewed program managers and contracting officers to determine the process used to award the two broadcasting contracts and a nongeneralizable selection of 37 talent services contracts."

Correspondence issued by the Government Accountability Office with an abstract that begins "The terrorist attacks of September 11, 2001, on the World Trade Center in New York City and the Pentagon in Arlington, Virginia, are estimated to have resulted in insured losses amounting to $32.5 billion. Subsequent to the attacks, insurers largely stopped offering terrorism insurance coverage to commercial property owners, which raised significant concerns about potential negative economic consequences. To help restore confidence and stability in property insurance markets, Congress enacted and the President signed the Terrorism Risk Insurance Act of 2002 (TRIA). Under TRIA, the federal government assumed significant responsibility for the potential insured financial losses associated with future terrorist attacks. While TRIA, which was reauthorized in 2005 and again in 2007, has been credited with stabilizing markets for commercial property insurance, some building owners, Members of Congress, and other industry participants remain concerned that there may still be gaps in coverage. In particular, they have expressed concerns about the ability of policyholders located in large urban areas that are viewed as being at high risk of attack to obtain terrorism insurance coverage. Under the 2007 statute that reauthorized TRIA coverage, GAO was required to conduct a study …

Correspondence issued by the Government Accountability Office with an abstract that begins "In February 2008, we issued our opinions on the calendar year 2007 financial statements of the Deposit Insurance Fund (DIF) and the FSLIC Resolution Fund (FRF). We also issued our opinion on the effectiveness of the Federal Deposit Insurance Corporation's (FDIC) internal control over financial reporting (including safeguarding assets) and compliance as of December 31, 2007, and our evaluation of FDIC's compliance with provisions of selected laws and regulations for the two funds for the year ended December 31, 2007. The purpose of this report is to present issues identified during our audits of the 2007 financial statements regarding certain internal controls and accounting procedures and to recommend actions to address these issues. Although these issues were not material in relation to the financial statements, we believe that they warrant management's attention. We are making five recommendations for strengthening FDIC's internal controls and accounting procedures. We conducted our audits in accordance with U.S. generally accepted government auditing standards."

A letter report issued by the Government Accountability Office with an abstract that begins "By law, facilities funded by the Indian Health Service (IHS) may retain reimbursement from Medicare and Medicaid without an offsetting reduction in funding. Ensuring that IHS-funded facilities enroll individuals in--and obtain reimbursement from--Medicare and Medicaid can provide an important means of expanding the funding for health care services for the population served by IHS. The Centers for Medicare & Medicaid Services (CMS), the agency within the Department of Health and Human Services (HHS) that administers Medicare and oversees states' Medicaid programs, is required by Executive Order and HHS policy to consult with Indian tribes on policies that have tribal implications. This requirement is in recognition of the unique government-to-government relationship between the 562 federally recognized Indian tribes and the federal government. GAO was asked to (1) describe interactions between CMS and IHS, (2) examine mechanisms CMS uses to interact and consult with Indian tribes, (3) examine mechanisms that selected states' Medicaid programs use to interact and consult with Indian tribes, and (4) identify barriers to Medicare and Medicaid enrollment and efforts to help eligible American Indians and Alaska Natives apply for and enroll in these programs. …

An RF power balance method is used to measure the synchrotron radiation losses and the wake field losses. We present the history of the losses in the Low Energy Ring (LER) and the High Energy Ring (HER) during the last several runs of PEP-II.

We investigate the couplings between different energy band valleys in a MOSFET device using self-consistent calculations of million-atom Schroedinger-Poisson Equations. Atomistic empirical pseudopotentials are used to describe the device Hamiltonian and the underlying bulk band structure. The MOSFET device is under nonequilibrium condition with a source-drain bias up to 2V, and a gate potential close to the threshold potential. We find that all the intervalley couplings are small, with the coupling constants less than 3 meV. As a result, the system eigenstates derived from different bulk valleys can be calculated separately. This will significantly reduce the simulation time, because the diagonalization of the Hamiltonian matrix scales as the third power of the total number of basis functions.

The Augustine Band of Cahuilla Indians was awarded a grant through the Department of Energy First Steps program in June of 2006. The primary purpose of the grant was to enable the Tribe to develop energy conservation policies and a strategy for alternative energy resource development. All of the work contemplated by the grant agreement has been completed and the Tribe has begun implementing the resource development strategy through the construction of a 1.0 MW grid-connected photovoltaic system designed to offset a portion of the energy demand generated by current and projected land uses on the Tribe’s Reservation. Implementation of proposed energy conservation policies will proceed more deliberately as the Tribe acquires economic development experience sufficient to evaluate more systematically the interrelationships between conservation and its economic development goals.

The electronic structure of multiferroic BiFeO{sub 3} has been studied using soft-X-ray emission spectroscopy. The fluorescence spectra exhibit that the valence band is mainly composed of O 2p state hybridized with Fe 3d state. The band gap corresponding to the energy separation between the top of the O 2p valence band and the bottom of the Fe 3d conduction band is 1.3 eV. The soft-X-ray Raman scattering reflects the features due to charge transfer transition from O 2p valence band to Fe 3d conduction band. These findings are similar to the result of electronic structure calculation by density functional theory within the local spin-density approximation that included the effect of Coulomb repulsion between localized d states.

Four isotopes of rutherfordium,254-257Rf, were produced by the 208Pb(48Ti, xn)256-xRf and 208Pb(50Ti, xn)258-xRf reactions (x = 1, 2) at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Excitation functions were measured for the 1n and 2n exit channels. A maximum likelihood technique, which correctly accounts for the changing cross section at all energies subtended by the targets, was used to fit the 1n data to allow a more direct comparison between excitation functions obtained under different experimental conditions. The maximum 1n crosssections of the 208Pb(48Ti, n)255Rf and 208Pb(50Ti, n)257Rf reactions obtained from fits to the experimental data are 0.38 +/- 0.07 nb and 40 +/-5 nb, respectively. Excitation functions for the 2n exit channel were also measured, with maximum cross sections of nb for the 48Ti induced reaction, and 15.7 +/- 0.2 nb for the 50Ti induced reaction. The impact of the two neutron difference in the projectile on the 1n cross section is discussed. The results are compared to the Fusion by Diffusion model developed by Swiatecki, Wilczynska, and Wilczynski.

The ultra-fast switching of power MOSFETs, in {approx}1ns, is very challenging. This is largely due to the parasitic inductance that is intrinsic to commercial packages used for both MOSFETs and drivers. Parasitic gate and source inductance not only limit the voltage rise time on the MOSFET internal gate structure but can also cause the gate voltage to oscillate. This paper describes a hybrid approach that substantially reduces the parasitic inductance between the driver and MOSFET gate as well as between the MOSFET source and its external connection. A flip chip assembly is used to directly attach the die-form power MOSFET and driver on a PCB. The parasitic inductances are significantly reduced by eliminating bond wires and minimizing lead length. The experimental results demonstrate ultra-fast switching of the power MOSFET with excellent control of the gate-source voltage.

This article summarizes the search for lepton flavor violating {tau} and B decays, using data collected by the BABAR detector at the PEP-II asymmetric-energy B factory.

This document describes highlights of science condcuted at EMSL during FY2008, 2nd Quarter.

Contrary to the conventional wisdom, electronic states in a 'well behaved' semiconductor alloy such as Ga{sub x}In{sub 1-x}P may drastically deviate from a Bloch state, which can be true even for band edge states if they are derived from degenerate critical points. For Ga{sub x}In{sub 1-x}P in the entire composition range, k-space spectral analyses are performed for the important critical points, revealing the significance of the (near) resonant inter-and intra-valley scatterings of the fluctuation potential in the alloy. The non-trivial implications of such scatterings on the transport and strain effect are discussed.

High-quality colloidal CdTe quantum wires having purposefully controlled diameters in the range of 5-11 nm are grown by the solution-liquid-solid (SLS) method, using Bi-nanoparticle catalysts, cadmium octadecylphosphonate and trioctylphosphine telluride as precursors, and a TOPO solvent. The wires adopt the wurtzite structure, and grow along the [002] direction (parallel to the c axis). The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to the experimental results for high-quality CdTe quantum dots. In contrast to the predictions of an effective-mass approximation, particle-in-a-box model, and previous experimental results from CdSe and InP dot-wire comparisons, the band gaps of CdTe dots and wires of like diameter are found to be experimentally indistinguishable. The present results are analyzed using density functional theory under the local-density approximation by implementing a charge-patching method. The higher-level theoretical analysis finds the general existence of a threshold diameter, above which dot and wire band gaps converge. The origin and magnitude of this threshold diameter is discussed.

We present a new linearly scaling three-dimensional fragment (LS3DF) method for large scale ab initio electronic structure calculations. LS3DF is based on a divide-and-conquer approach, which incorporates a novel patching scheme that effectively cancels out the artificial boundary effects due to the subdivision of the system. As a consequence, the LS3DF program yields essentially the same results as direct density functional theory (DFT) calculations. The fragments of the LS3DF algorithm can be calculated separately with different groups of processors. This leads to almost perfect parallelization on tens of thousands of processors. After code optimization, we were able to achieve 35.1 Tflop/s, which is 39% of the theoretical speed on 17,280 Cray XT4 processor cores. Our 13,824-atom ZnTeO alloy calculation runs 400 times faster than a direct DFT calculation, even presuming that the direct DFT calculation can scale well up to 17,280 processor cores. These results demonstrate the applicability of the LS3DF method to material simulations, the advantage of using linearly scaling algorithms over conventional O(N{sup 3}) methods, and the potential for petascale computation using the LS3DF method.

At the Savannah River Site (SRS), near Aiken South Carolina, there is a crucial need to remove residual quantities of highly radioactive iron-based sludge from large select underground storage tanks (e.g., 19,000 liters of sludge per tank), in order to support tank closure. The use of oxalic acid is planned to dissolve the residual sludge, hence, helping in the removal. Based on rigorous testing, primarily using 4 and 8 wt% oxalic acid solutions, it was concluded that the more concentrated the acid, the greater the amount of residual sludge that would be dissolved; hence, a baseline technology on using 8 wt% oxalic acid was developed. In stark contrast to the baseline technology, reports from other industries suggest that the dissolution will most effectively occur at 1 wt% oxalic acid (i.e., maintaining the pH near 2). The driver for using less oxalic acid is that less (i.e., moles) would decrease the severity of the downstream impacts (i.e., required oxalate solids removal efforts). To determine the initial feasibility of using 1 wt% acid to dissolve > 90% of the sludge solids, about 19,000 liters of representative sludge was modeled using about 530,000 liters of 0 to 8 wt% oxalic acid solutions. With …

We present a new linear scaling ab initio total energy electronic structure calculation method based on the divide-and-conquer strategy. This method is simple to implement, easily to parallelize, and produces very accurate results when compared with the direct ab initio method. The method has been tested using up to 8,000 processors, and has been used to calculate nanosystems up to 15,000 atoms.

The cleaning of Si{sub 0.85}Ge{sub 0.15} surfaces using HCl and HF solutions is studied using synchrotron radiation photoelectron spectroscopy. The HF solution is found to be effective in removing both the Si oxide and the Ge oxide while the HCl solution can only remove part of the Ge oxide. For samples treated with HF, four spectral components are needed to fit the Ge 3d photoemission spectra. One is the bulk component and the other three are attributed to the surface Ge atoms with mono-hydride, di-hydride and tri-hydride terminations, respectively.

Intrabeam scattering (IBS) of electrons in the pre-cathode area in the electron guns know in the literature as Boersh effect is responsible for a growth of the electron beam energy spread there. Albeit most visible within the electron gun where the electron beam density is large and the energy spread is small, the IBS acts all along the entire electron beam pass through the Linac. In this report we calculate the energy spread induced by IBS in the FERMI@elettra electron gun.

The electronic structures of BiFeO{sub 3} (BF) and Mn-doped BiFeO{sub 3} (BF(Mn)) have been studied by X-ray absorption spectroscopy (XAS) and soft-X-ray emission spectroscopy (SXES). The BF and BF(Mn) have the mixed valence state of Fe{sup 2+} and Fe{sup 3+}. The valence band is mainly composed of O 2p state hybridized with the majority-spin t{sub 2g} and e{sub g} orbitals of Fe 3d state. The conduction band is composed of the minority-spin t{sub 2g} and e{sub g} orbitals of Fe 3d. The band gaps of BF and BF(Mn) are estimated to be 1.3 eV and 2.7 eV, respectively. The increase of band gap with Mn substitution contributes to the change of bandwidth of valence band.

We present a fully 3D atomistic quantum mechanical simulation for nanometered MOSFET using a coupled Schroedinger equation and Poisson equation approach. Empirical pseudopotential is used to represent the single particle Hamiltonian and linear combination of bulk band (LCBB) method is used to solve the million atom Schroedinger's equation. We studied gate threshold fluctuations and threshold lowering due to the discrete dopant configurations. We compared our results with semiclassical simulation results. We found quantum mechanical effects increase the threshold fluctuation while decreases the threshold lowering. The increase of threshold fluctuation is in agreement with previous study based on approximated density gradient approach to represent the quantum mechanical effect. However, the decrease in threshold lowering is in contrast with the previous density gradient calculations.

During PEP-II operation with high currents in the High Energy Ring (HER), elevated temperatures were found at many locations in the vacuum chamber where they have an RF seal for the flex flange. Most of these omega RF seals were badly damaged and had evidence of metal vaporization from sparks and electrical discharge. They suggest a physical model, which may explain this effect.

The Saltstone Facility is designed and permitted to immobilize and dispose of low-level radioactive and hazardous liquid waste (salt solution) remaining from the processing of radioactive material at the Savannah River Site. Low activity wastewater streams from the Effluent Treatment Project (ETP), H-Canyon, and the high level waste (HLW) storage tanks, are stored as a mixture in Tank 50H until it can be pumped to the Saltstone Facility for treatment and disposal. Specific waste acceptance criteria (WAC) must be met for the transfer of low-level aqueous waste from Tank 50H to the Saltstone Facility. Low level waste which meets the WAC can be transferred, stored and treated in the Saltstone Production Facility (SPF) for subsequent disposal as saltstone in the Saltstone Disposal Facility (SDF). Waste Solidification Engineering (WSE) has requested through a Technical Task Request (TTR) that the Savannah River National Laboratory (SRNL) measure the concentrations of chemical and radionuclide contaminants listed in the currently approved Saltstone Waste Acceptance Criteria (WAC). A Task Technical and Quality Assurance Plan and Analytical Study Plan has been written for this request. WAC determinations are needed on a quarterly basis for chemical contaminants and every first and third quarter for radioactive contaminants. This memorandum …