Modern tools of radiobiology are leading to many new discoveries regarding how cells and tissues respond to radiation exposure. We can now irradiate single cells and observe responses in adjacent cells. We can also measure clusters of radiation damage produced in DNA. Our primary objective has been to understand the underling physics associated with these new biological responses. The primary tools available to describe the initial spatial pattern of damage formed by the absorption of ionizing radiation are based on Monte Carlo simulation of the structure of charged particle tracks. Although many Monte Carlo codes exist and considerable progress is being made in the incorporation of detailed macromolecular target structures into these codes, much of the interaction physics is still based on gas phase measurements and/or untested theoretical calculations that focus on water as the transport medium. Our objectives were threefold, (1) to expand the applicability of Monte Carlo track structure simulation to tissue-like material beyond the current focus on water, (2) to incorporate the most recent experimental information on electron interactions in biologically relevant material, and (3) to compare recent measurements of electron emissions induced by charged particles in thin foils with Monte Carlo predictions. We addressed these research …

This report provides data on the distribution of assets i estates as reported on estate tax returns filed in 2005. This report finds that farm and business assets represents a small share of the total value of taxable estates that file tax returns in 2005.

This report is about Broadband Internet Access and the Digital Divide: Federal Assistance Programs.

Concern has grown in Congress and elsewhere about China's military modernization. The topic is an increasing factor in discussions over future required U.S. Navy capabilities. The issue for Congress addressed in this report is: How should China's military modernization be factored into decisions about U.S. Navy programs?

The 105-K East (KE) Basin Ion Exchange Column (IXC) cells, lead caves, and the surrounding vault are to be removed as necessary components in implementing ''Hanford Federal Facility Agreement and Consert Order'' (Ecology et al. 2003) milestone M-034-32 (Complete Removal of the K East Basin Structure). The IXCs consist of six units located in the KE Basin, three in operating positions in cells and three stored in a lead cave. Methods to remove the IXCs from the KE Basin were evaluated in KBC-28343, ''Disposal of K East Basin Ion Exchange Column Evaluation''. The method selected for removal was grouting of the six IXCs into a single monolith for disposal at the Environmental Restoration Disposal Facility (ERDF). Grout will be added to the IXC cells, IXC lead caves containing spent IXCs, and in the spaces between to immobilize the contaminants, provide self-shielding, minimize void space, and provide a structurally stable waste form. The waste to be offered for disposal is the encapsulated monolith defined by the exterior surfaces of the vault and the lower surface of the underlying slab. This document presents a summary of the data quality objective (DQO) process establishing the decisions and data required to support decision-making activities …

The final weeks of male germ cell differentiation occur in aDNA repair-deficient environment and normal development depends on theability of the egg to repair DNA damage in the fertilizing sperm. Geneticdisruption of maternal DNA double-strand break repair pathways in micesignificantly increased the frequency of zygotes with chromosomalstructural aberrations after paternal exposure to ionizing radiation.These findings demonstrate that radiation-induced DNA sperm lesions arerepaired after fertilization by maternal factors and suggest that geneticvariation in maternal DNA repair can modulate the risk of early pregnancylosses and of children with chromosomal aberrations of paternalorigin.

The waste disposal to the M-area basin and A-14 outfall at the Savannah River Department of Energy facility in Aiken SC (USA) included a wide variety of inorganic aqueous flows and organic solvents in the form of dense non-aqueous phase liquids (DNAPL). The DNAPL has migrated through the subsurface resulting in widespread groundwater contamination. The goal of this research was to identify and quantify processes that could have affected the migration and remediation of the DNAPL in the subsurface. It was hypothesized that the variety of waste disposed at this site could have altered the mineral, microbial and DNAPL properties at this site relative to other DNAPL sites. The DNAPL was determined to have a very low interfacial tension and is suspected to be distributed in fine grained media, thereby reducing the effectiveness of soil vapor extraction remediation efforts. Although the DNAPL is primarily comprised of tetrachloroethene and trichloroethane, it also contains organic acids and several heavy metals. Experimental results suggest that iron from the aqueous and DNAPL phases undergoes precipitation and dechlorination reactions at the DNAPL-water interface, contributing to the low interfacial tension and acidity of the DNAPL. Biological activity in the contaminated region can also contribute to the …

Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate, including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash.

In this article the effect of different engineering parameters of an rf-driven ion sources with external spiral antenna and quartz disk rf-window are studied. Paper consists of three main topics: The effect of source geometry on the operation gas pressure, the effect of source materials and magnetic confinement on extracted current density and ion species and the effect of different antenna geometries on the extracted current density. The operation gas pressure as a function of the plasma chamber diameter, was studied. This was done with three cylindrical plasma chambers with different inner diameters. The chamber materials were studied using two materials, aluminum and alumina (AlO{sub 2}). The removable 14 magnet multicusp confinement arrangement enabled us to compare the effects of the two wall materials with and without the magnetic confinement. Highest proton fraction of {approx} 8% at 2000 W of rf-power and at pressure of 1.3 Pa was measured using AlO{sub 2} plasma chamber and no multicusp confinement. For all the compared ion sources at 1000W of rf-power, source with multicusp confinement and AlO2 plasma chamber yields highest current density of 82.7 mA/cm{sup 2} at operation pressure of 4 Pa. From the same source highest measured current density of 143 …

This report summarizes principal federal disaster assistance programs for possible use by Members of Congress and their staff in helping address the needs of constituents. This report includes a list of CRS reports about disaster assistance and assistance for victims of recent hurricanes. It also includes a list of federal agencies' websites established specifically to respond to disasters, offering updates on recovery efforts, and providing a catalog of federal assistance programs.

Numerous federal, state, and local agencies share responsibilities for regulating the safety of the U.S. food supply, which many experts say is among the safest in the world. Nevertheless, critics view this system as lacking the organization and resources to adequately combat foodborne illness, which sickens an estimated 76 million people and kills an estimated 5,000 each year in this country. The 110th Congress may face calls for a review of federal food safety agencies and authorities, and proposals for reorganizing them. Among the issues likely to arise are whether reform can improve oversight, and the cost to industry, consumers, and taxpayers. This report provides a brief introduction to the system and the debate on whether reorganization is needed.

Using a simple set of poloidal field coils, one can reach the situation where the null of the poloidal magnetic field in the divertor region is of a second order, not of the first order as in the usual X-point divertor. Then, the separatrix in the vicinity of the null-point splits the poloidal plane not into four sectors, but into six sectors, making the whole structure looking like a snow-flake (whence a name, [1]). This arrangement allows one to spread the heat load over much broader area than in the case of a standard divertor. A disadvantage of this configuration is in that it is topologically unstable, and, with the current in the plasma varying with time, it would switch either to the standard X-point mode, or to the mode with two X-points close to each other. To avoid this problem, it is suggested to have a current in the divertor coils by roughly 5% higher than in an 'optimum' regime (the one where a snow-flake separatrix is formed). In this mode, the configuration becomes stable and can be controlled by varying the current in the divertor coils in concert with the plasma current; on the other hand, a strong …

Ultra-dense hydrogen has long been the subject of intense experimental and theoretical research due to the fascinating physics which arises from this supposedly simple system. The properties of ultra-dense hydrogen also have important implications for planetary physics, since the interiors of the giant planets Jupiter and Saturn are believed to consist of cores of dense, metallic hydrogen. Finally, ultra-dense hydrogen is of direct programmatic interest, and multiple-shock compression experiments on hydrogen to the metallic state have stimulated the accelerated development of new hydrogen equation-of-state (EOS) models used for ICF and other applications. The focus of our research has often been described as the ''Holy Grail'' of high-pressure physics research: The metallization of solid hydrogen. Metallic hydrogen has long been considered to be the prototypical system for the study of insulator-to-metal (I-M) transitions. Although metallic hydrogen (Z=1) may superficially appear to be a very simple material, it is in fact an extremely challenging system for theoretical analysis due to the presence of large zero-point atomic motions and the complete absence of any core electrons. Thus, solid metallic hydrogen promises to be a fascinating material. Among its predicted properties is the possibility of being a high temperature superconductor with a critical temperature …

Testimony issued by the Government Accountability Office with an abstract that begins "Since the terrorist attacks of September 11, 2001, and the subsequent creation of the Department of Homeland Security (DHS), the federal government has provided DHS with more than $130 billion in budget authority to make investments in homeland security. However, as GAO has reported, this federal financial assistance has not been guided by a clear risk-based strategic plan that fully applies risk management principles. This testimony discusses the extent to which DHS has taken steps to apply risk management principles to target federal funding for homeland security investments (1) in making grant allocations, (2) in funding transportation and port security enhancements, (3) in other DHS mission areas, and (4) at a strategic level across DHS. This testimony summarizes previous GAO work in these areas."

Correspondence issued by the Government Accountability Office with an abstract that begins "In fiscal year 2006, the Department of Homeland Security (DHS) provided approximately $1.7 billion in federal funding to states, localities, and territories through its Homeland Security Grant Program (HSGP) to prevent, protect against, respond to, and recover from acts of terrorism or other catastrophic events. The Urban Areas Security Initiative (UASI) is a discretionary grant under this program, and since fiscal year 2003, Congress has directed DHS to target UASI funding to high-threat, high-density urban areas to assist in building capacity. To meet this requirement and inform funding decisions, DHS developed a method to estimate the relative risk of terrorist attacks to urban areas. From fiscal year 2003 through 2005, DHS used a number of risk indicators such as population density and threat to allocate UASI funds. UASI funding increased during this period from about $96 million to $830 million, while the number of urban areas that received grants grew from 7 to 43. In fiscal year 2006, DHS awarded approximately $711 million in UASI grants--a 14 percent reduction in funds from the previous year--while the number of eligible urban areas identified by the risk assessment decreased to …

Testimony issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security (DHS) plays a key role in leading and coordinating--with stakeholders in the federal, state, local, and private sectors--the nation's homeland security efforts. GAO has conducted numerous reviews of DHS management functions as well as programs including transportation and border security, immigration enforcement and service delivery, and disaster preparation and response. This testimony addresses: (1) why GAO designated DHS's implementation and transformation as a high-risk area, (2) management challenges facing DHS, (3) programmatic challenges facing DHS, and (4) actions DHS should take to strengthen its implementation and transformation efforts."

A letter report issued by the Government Accountability Office with an abstract that begins "Hurricanes Katrina and Rita displaced over 1 million people and affected some of the poorest areas of the country. Many of those affected by the hurricanes received federal assistance from the Old Age, Survivors, and Disability Insurance (Social Security), Supplemental Security Income (SSI), Food Stamp, Unemployment Insurance (UI), and Temporary Assistance for Needy Families (TANF) programs beforehand and others were newly eligible after the storms. Under the Comptroller General's authority, GAO assessed the (1) challenges the hurricanes created for programs to take applications and pay benefits, (2) factors that helped or hindered programs' efforts, and (3) areas that warrant further attention and actions being taken to improve programs' disaster response. To do this work, GAO reviewed policies, reports, and plans, and interviewed program officials at the federal level and in Alabama, Florida, Louisiana, Mississippi, and Texas."

This report lists significant recent events in Iraq.

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CH2M HILL Hanford Group, Inc. (CH2M HILL) is pleased to nominate the Integrated Disposal Facility (IDF) project for the Project Management Institute's consideration as 2007 Project of the Year, Built for the U.S, Department of Energy's (DOE) Office of River Protection (ORP) at the Hanford Site, the IDF is the site's first Resource Conservation and Recovery Act (RCRA)-compliant disposal facility. The IDF is important to DOE's waste management strategy for the site. Effective management of the IDF project contributed to the project's success. The project was carefully managed to meet three Tri-Party Agreement (TPA) milestones. The completed facility fully satisfied the needs and expectations of the client, regulators and stakeholders. Ultimately, the project, initially estimated to require 48 months and $33.9 million to build, was completed four months ahead of schedule and $11.1 million under budget. DOE directed construction of the IDF to provide additional capacity for disposing of low-level radioactive and mixed (i.e., radioactive and hazardous) solid waste. The facility needed to comply with federal and Washington State environmental laws and meet TPA milestones. The facility had to accommodate over one million cubic yards of the waste material, including immobilized low-activity waste packages from the Waste Treatment Plant (WTP), …

The Federal Aviation Administration (FAA) identified 17 accidents that may have resulted from fuel tank explosions on commercial aircraft from 1959 to 2001. Seven events involved JP 4 or JP 4/Jet A mixtures that are no longer used for commercial aircraft fuel. The remaining 10 events involved Jet A or Jet A1 fuels that are in current use by the commercial aircraft industry. Four fuel tank explosions occurred in center wing tanks (CWTs) where on-board appliances can potentially transfer heat to the tank. These tanks are designated as ''Heated Center Wing Tanks'' (HCWT). Since 1996, the FAA has significantly increased the rate at which it has mandated airworthiness directives (ADs) directed at elimination of ignition sources. This effort includes the adoption, in 2001, of Special Federal Aviation Regulation 88 of 14 CFR part 21 (SFAR 88 ''Fuel Tank System Fault Tolerance Evaluation Requirements''). This paper addresses SFAR 88 effectiveness in reducing HCWT ignition source probability. Our statistical analysis, relating the occurrence of both on-ground and in-flight HCWT explosions to the cumulative flight hours of commercial passenger aircraft containing HCWT's reveals that the best estimate of HCWT explosion rate is 1 explosion in 1.4 x 10{sup 8} flight hours. Based on …

In large-scale geologic storage projects, the injected volumes of CO{sub 2} will displace huge volumes of native brine. If the designated storage formation is a closed system, e.g., a geologic unit that is compartmentalized by (almost) impermeable sealing units and/or sealing faults, the native brine cannot (easily) escape from the target reservoir. Thus the amount of supercritical CO{sub 2} that can be stored in such a system depends ultimately on how much pore space can be made available for the added fluid owing to the compressibility of the pore structure and the fluids. To evaluate storage capacity in such closed systems, we have conducted a modeling study simulating CO{sub 2} injection into idealized deep saline aquifers that have no (or limited) interaction with overlying, underlying, and/or adjacent units. Our focus is to evaluate the storage capacity of closed systems as a function of various reservoir parameters, hydraulic properties, compressibilities, depth, boundaries, etc. Accounting for multi-phase flow effects including dissolution of CO{sub 2} in numerical simulations, the goal is to develop simple analytical expressions that provide estimates for storage capacity and pressure buildup in such closed systems.

We measured dielectric permittivity of dry and fluid-saturated Green River oil shale samples over a frequency range of 1 MHz to 1.8 GHz. Dry sample measurements were carried out between room temperature and 146 C, saturated sample measurements were carried out at room temperature. Samples obtained from the Green River formation of Wyoming and from the Anvil Points Mine in Colorado were cored both parallel and perpendicular to layering. The samples, which all had organic richness in the range of 10-45 gal/ton, showed small variations between samples and a relatively small level of anisotropy of the dielectric properties when dry. The real and imaginary part of the relative dielectric permittivity of dry rock was nearly constant over the frequency range observed, with low values for the imaginary part (loss factor). Saturation with de-ionized water and brine greatly increased the values of the real and imaginary parts of the relative permittivity, especially at the lower frequencies. Temperature effects were relatively small, with initial increases in permittivity to about 60 C, followed by slight decreases in permittivity that diminished as temperature increased. Implications of these observations for the in situ electromagnetic, or radio frequency (RF) heating of oil shale to produce oil …

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