Clouds of stray electrons are ubiquitous in particle accelerators and frequently limit the performance of storage rings. Earlier measurements of electron energy distribution and flux to the walls provided only a relative electron cloud density. We have measured electron accumulation using ions expelled by the beam. The ion energy distribution maps the depressed beam potential and gives the dynamic cloud density. Clearing electrode current reveals the static background cloud density, allowing the first absolute measurement of the time-dependent electron cloud density during the beam pulse.

The BABAR Silicon Vertex Tracker (SVT) has been efficiently operated for six years since the start of data taking in 1999. Due to higher than expected background levels some unforeseen effects have appeared. We discuss: a shift in the pedestal for the channels of the AToM readout chips that are most exposed to radiation; an anomalous increase in the bias leakage current for the modules in the outer layers. Estimates of future radiation doses and occupancies are shown together with the extrapolated detector performance and lifetime, in light of the new observations.

Testimony issued by the Government Accountability Office with an abstract that begins "This testimony focuses on the Architect of the Capitol's progress in achieving selected project milestones and in managing the project's schedule since Congress's March 15, 2006, hearing on the project. As part of this discussion, we will address a number of key challenges and risks that continue to face the project, as well as actions AOC has taken or plans to take to address these risks. In addition, we will discuss the status of the project's costs and funding."

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Re-entry vehicles on missiles launched at Vandenberg Air Force base in California re-enter at the Western Test Range, the Regan Test Site (RTS) at Kwajalein Atoll. An environmental Assessment (EA) was written at the beginning of the program to assess potential impact of Depleted Uranium (DU) and Beryllium (Be), the major RV materials of interest from a health and environmental perspective. The chemical and structural form of DU and Be in RVs is such that they are insoluble in soil water and sea water. Consequently, residual concentrations of DU and Be observed in soil on the island are not expected to be toxic to plant life because there is essentially no soil to plant uptake. Similarly, due to their insolubility in sea water there is no uptake of either element by marine biota including fish, mollusks, shellfish and sea mammals. No increase in either element has been observed in sea life around Illeginni Island where deposition of DU and Be has occurred. The critical terrestrial exposure pathway for U and Be is inhalation. Concentration of both elements in air over the test period (1989 to 2006) is lower by a factor of 10,000 than the most restrictive U.S. guideline for …

A letter report issued by the Government Accountability Office with an abstract that begins "Alaska Native corporations (ANC) were created to settle land claims with Alaska Natives and foster economic development. In 1986, legislation passed that allowed ANCs to participate in the Small Business Administration's (SBA) 8(a) program. Since then, Congress has extended special procurement advantages to 8(a) ANC firms, such as the ability to win sole-source contracts for any dollar amount. This report identifies (1) trends in the government's 8(a) contracting with ANC firms, (2) the reasons agencies have awarded 8(a) sole-source contracts to ANC firms and the facts and circumstances behind some of these contracts, and (3) how ANCs are using the 8(a) program. GAO also evaluated SBA's oversight of 8(a) ANC firms."

The Safe Drinking Water Act Amendments of 1996 authorized a drinking water state revolving loan fund program to help public water systems finance infrastructure projects needed to comply with federal drinking water regulations and to protect public health.

The goals of this study are: (1) to configure a thermal-hydrological, natural-ventilation model for simulating temperature, humidity, and condensate distributions in the coupled domains of in-drift airspace and near-field rockmass. Rokmass model: TOUGH2, in-drift model: MULTIFLUX (MF); (2) obtain meaningful results from the model for a practical application in which the beneficial effects of unheated drift sections are analyzed; and (3) study the sensitivity to the axial dispersion coefficient with the model.

This report discusses about energy tax policy. U.S energy tax policy promoted the supply of oil and gas but witnessed significant cutback, imposition of new excise taxes on oil and introduction of numerous tax preferences for energy conservation.

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Testimony issued by the Government Accountability Office with an abstract that begins "About a dozen people are killed or injured in natural gas transmission pipeline incidents each year. In an effort to improve upon this safety record, the Pipeline Safety Improvement Act of 2002 requires that operators assess pipeline segments in about 20,000 miles of highly populated or frequented areas for safety risks, such as corrosion, welding defects, or incorrect operation. Half of these baseline assessments must be done by December 2007, and the remainder by December 2012. Operators must then repair or replace any defective pipelines, and reassess these pipeline segments for corrosion damage at least every 7 years. The Pipeline and Hazardous Materials Safety Administration (PHMSA) administers this program, called gas integrity management. This testimony is based on ongoing work for this Subcommittee and for other committees, as required by the 2002 act. The testimony provides preliminary results on the safety effects of (1) PHMSA's gas integrity management program and (2) the requirement that operators reassess their natural gas pipelines at least every 7 years. It also discusses how PHMSA has acted to strengthen its enforcement program in response to recommendations GAO made in 2004. GAO expects to …

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The development in the 1950's and 60's of crossed molecular beam methods for studying chemical reactions at the single-collision molecular level stimulated the need and desire for theoretical methods to describe these and other dynamical processes in molecular systems. Chemical dynamics theory has made great strides in the ensuing decades, so that methods are now available for treating the quantum dynamics of small molecular systems essentially completely. For the large molecular systems that are of so much interest nowadays (e.g. chemical reactions in solution, in clusters, in nano-structures, in biological systems, etc.), however, the only generally available theoretical approach is classical molecular dynamics (MD) simulations. Much effort is currently being devoted to the development of approaches for describing the quantum dynamics of these complex systems. This paper reviews some of these approaches, especially the use of semiclassical approximations for adding quantum effects to classical MD simulations, also showing some new versions that should make these semiclassical approaches even more practical and accurate.

Testimony issued by the Government Accountability Office with an abstract that begins "The Internal Revenue Service's (IRS) filing season performance affects tens of millions of taxpayers who expect timely refunds and accurate answers to their tax questions. IRS's budget request is a planning tool showing how it intends to provide taxpayer service and enforce the tax laws in 2007. It is also the first in a series of annual steps that will determine whether IRS meets its new long-term goals of increasing tax compliance and reducing taxpayers' acceptance of cheating on their taxes. Tax law enforcement remains on GAO's list of high-risk federal programs, in part, because of the persistence of a large tax gap. IRS recently estimated the gross tax gap, the difference between what taxpayers owe and what they voluntarily pay, to be $345 billion for 2001. GAO assessed (1) IRS's interim 2006 filing season performance; (2) the budget request; and (3) how the budget helps IRS achieve its longterm goals. GAO compared performance and the requested budget to previous years."

iSHIELD11 performs a line-source numerical integration of radiation source terms that are defined by the iSHIELD11 computer code[1] . An example is provided to demonstrate how one can use iSHIELD11 to perform a shielding analysis for a 250 GeV electron linear accelerator.

A systematic approach to manage hydrogen leakage from components is presented. Methods to evaluate the quantity of hydrogen leakage and permeation from a system are provided by calculation and testing sensitivities. The following technology components of a leak management program are described: (1) Methods to evaluate hydrogen gas loss through leaks; (2) Methods to calculate opening areas of crack like defects; (3) Permeation of hydrogen through metallic piping; (4) Code requirements for acceptable flammability limits; (5) Methods to detect flammable gas; (6) Requirements for adequate ventilation in the vicinity of the hydrogen system; (7) Methods to calculate dilution air requirements for flammable gas mixtures; and (8) Concepts for reduced leakage component selection and permeation barriers.

A letter report issued by the Government Accountability Office with an abstract that begins "As part of the Committee on Government Reform's continuing focus on pay and financial issues affecting Army soldiers deployed in the Global War on Terrorism (GWOT), the requesters were concerned that battle-injured soldiers were not only battling the broken military pay system, but faced blemishes on their credit reports and pursuit by collection agencies from referrals of their Army debts. GAO was asked to determine (1) the extent of debt of separated battle-injured soldiers and deceased Army soldiers who served in the GWOT, (2) the impact of DOD debt collection action on separated battle-injured and deceased soldiers and their families, and (3) ways that Congress could make the process for collecting these debts more soldier friendly."

Correspondence issued by the Government Accountability Office with an abstract that begins "Over the past several years, we have reported on significant pay problems experienced by mobilized Army National Guard and Army Reserve (Army Guard and Reserve) soldiers in the wake of the September 11, 2001, terrorist attack. These reports included examples of hundreds of soldiers receiving inaccurate and untimely payroll payments due to a paper-intensive, error-prone pay process and the lack of integrated pay and personnel systems. In response to our reports, the Department of Defense (DOD) has taken some action to improve controls designed to pay Army Guard and Reserve soldiers accurately and on time, especially those who had become sick or injured in the line of duty. This report responds to a Congressional request that we investigate the allegation that 37 Army Guard and Reserve soldiers assigned to the Medical Retention Processing Unit (MRPU) at Fort Bragg, North Carolina, were overpaid for hostile fire and hardship duty pay while in an outpatient status. Our objectives were to determine (1) whether the allegations were true, and if so, whether the pay issues were more widespread at Fort Bragg and (2) the key causes of the overpayments and the …

Testimony issued by the Government Accountability Office with an abstract that begins "In light of GAO's past four reports and testimonies on Army military pay and travel pay for soldiers who have served in the Global War on Terrorism (GWOT), GAO was asked to determine if weaknesses in Army processes for initiating and terminating active duty pay might result in erroneous payments and debt, including (1) overpayments to soldiers in the Fort Brag Medical Retention Processing Unit (MRPU)--1 of 23 MRPUs--and (2) overpayments and other errors that resulted in debt collection action against battle-injured soldiers who were released from active duty. GAO also was asked to develop case studies to illustrate the effects of these problems on soldiers and their families and to determine ways that Congress could make the debt collection process more soldier friendly."

A letter report issued by the Government Accountability Office with an abstract that begins "The President's Vision for Space Exploration calls for human and robotic missions to the Moon, Mars, and beyond. In response, over the next two decades, NASA may spend $100 billion on new technologies and facilities that will require reliable ground communications to achieve those missions. Presently, that communications capability is provided by NASA's Deep Space Network--a system of antennas located at three sites around the world. However, the Network faces challenges that may hinder its provision of current and future mission support. This report discusses (1) the significant operational challenges faced by the Deep Space Network and (2) the extent to which NASA is integrating the Network into its future communications plans."

Testimony issued by the Government Accountability Office with an abstract that begins "The federal government is placing greater emphasis on thinning vegetation on public lands to reduce the risk of wildland fire. To help defray the cost of thinning efforts, it also is seeking to stimulate a market for the resulting material, including the smaller trees, limbs, and brush--referred to as woody biomass--that traditionally have had little or no commercial value. As GAO has reported in the past, the increased use of woody biomass faces obstacles, including the high cost of harvesting and transporting it and an unpredictable supply in some locations. Nevertheless, some entities, such as schools and businesses, are utilizing the material, potentially offering insights for broadening its use. GAO agreed to (1) identify key factors facilitating the use of woody biomass among selected users, (2) identify challenges these users have faced in using woody biomass, and (3) discuss any insights that these findings may offer for promoting greater use of woody biomass. This testimony is based on GAO's report Natural Resources: Woody Biomass Users' Experiences Offer Insights for Government Efforts Aimed at Promoting Its Use (GAO-06-336)."

A comprehensive test ban treaty, or CTBT, is the oldest item on the nuclear arms control agenda. Three treaties currently limit testing to underground only, with a maximum force equal to 150,000 tons of TNT. According to the Natural Resources Defense Council, the United States conducted 1,030 nuclear tests, the Soviet Union 715, the United Kingdom 45, France 210, and China 45. The last U.S. test was held in 1992; the last U.K. test, in 1991. Russia claims it has not conducted nuclear tests since 1991.

Atmospheric general circulation models (GCMs) used to project climate responses to increased CO{sub 2} generally omit irrigation of agricultural land. Using the NCAR CAM3 GCM coupled to a slab-ocean model, we find that inclusion of an extreme irrigation scenario has a small effect on the simulated temperature and precipitation response to doubled CO{sub 2} in most regions, but reduced warming by as much as 1 C in some agricultural regions, such as Europe and India. This interaction between CO{sub 2} and irrigation occurs in cases where agriculture is a major fraction of the land surface and where, in the absence of irrigation, soil moisture declines are projected to provide a positive feedback to temperature change. The reduction of warming is less than 25% of the temperature increase modeled for doubled CO{sub 2} in most regions; thus greenhouse warming will still be dominant. However, the results indicate that land use interactions may be an important component of climate change uncertainty in some agricultural regions. While irrigated lands comprise only {approx}2% of the land surface, they contribute over 40% of global food production. Climate changes in these regions are therefore particularly important to society despite their relatively small contribution to average global …

Testimony issued by the Government Accountability Office with an abstract that begins "The CARE Act, a federal effort to address the HIV/AIDS epidemic, is administered by HHS. The Act uses formulas based upon a grantee's number of AIDS cases to distribute funds to eligible metropolitan areas (EMA), states, and territories. The use of AIDS cases was prescribed because most jurisdictions tracked and reported only AIDS cases when the grant programs were established. HIV cases must be incorporated with AIDS cases in CARE Act formulas no later than fiscal year 2007. GAO was asked to discuss factors that affect the distribution of CARE Act funding. This testimony is based on HIV/AIDS: Changes Needed to Improve the Distribution of Ryan White CARE Act and Housing Funds, GAO-06-332 (Feb. 28, 2006). GAO discusses how specific funding-formula provisions contribute to funding differences among CARE Act grantees and what distribution differences could result from using HIV cases in CARE Act funding formulas."