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New developments in vibration analysis better explain machinery resonance, through an example of drill bit chattering during machining of rusted steel. The vibration of an operating drill motor was measured, the natural frequency of an attached spring was measured, and the two frequencies were compared to show that the system was resonant. For resonance to occur, one of the natural frequencies of a structural component must be excited by a cyclic force of the same frequency. In this case, the frequency of drill bit chattering due to motor rotation equaled the spring frequency (cycles per second), and the system was unstable. A soft rust coating on the steel to be drilled permitted chattering to start at the drill bit tip, and the bit oscillated on and off of the surface, which increased the wear rate of the drill bit. This resonant condition is typically referred to as a motor critical speed. The analysis presented here quantifies the vibration associated with this particular critical speed problem, using novel techniques to describe resonance.

Testimony issued by the Government Accountability Office with an abstract that begins "In March 2008, GAO designated the 2010 Census a high-risk area in part because of information technology (IT) shortcomings and uncertainty over the ultimate cost of the census, now estimated at around $15 billion. The U.S. Census Bureau (Bureau) has since made improvements to various IT systems and taken other steps to mitigate the risks of a successful census. However, last year, GAO noted that a number of challenges and uncertainties remained, and much work remained to be completed under very tight time frames. As requested, this testimony provides an update on the Bureau's readiness for an effective headcount, covering (1) the status of key IT systems; (2) steps the Bureau has taken to revise its cost estimates; and (3) the extent to which critical enumeration activities, particularly those aimed at hard-to-count populations, are on track. The testimony is based on previously issued and ongoing GAO work."

This report discusses the Implementation and issues related to Broadband Infrastructure Programs in the American Recovery and Reinvestment Act of 2009.

A promising approach for improving the efficiency of internal combustion engines is to employ a working fluid with a high specific heat ratio such as the noble gas argon. Moreover, all harmful emissions are eliminated when the intake charge is composed of oxygen, nonreactive argon, and hydrogen fuel. Previous research demonstrated indicated thermal efficiencies greater than 45% at 5.5 compression ratio in engines operating with hydrogen, oxygen, and argon. However, knock limits spark advance and increasing the efficiency further. Conditions under which knock occurs in such engines differs from typical gasoline fueled engines. In-cylinder temperatures using hydrogen-oxygen-argon are higher due to the high specific heat ratio and pressures are lower because of the low compression ratio. Better understanding of knock under these conditions can lead to operating strategies that inhibit knock and allow operation closer to the knock limit. In this work we compare knock with a hydrogen, oxygen, and argon mixture to that of air-gasoline mixtures in a variable compression ratio cooperative fuels research (CFR) engine. The focus is on stability of knocking phenomena, as well as, amplitude and frequency of the resulting pressure waves.

This report presents characterization data for two spherical resorcinol-formaldehyde (sRF) resin beds that had processed cesium in non-radioactive and radioactive cycles. All column cycle operations for the resin beds including loading, displacements, elution, regeneration, breakthroughs, and solution analyses are reported in Nash and Duignan, 2009a. That report covered four ion exchange (IX) campaigns using the two {approx}11 mL beds in columns in a lead-lag arrangement. The first two campaigns used Savannah River Site (SRS) Tank 2F nonradioactive simulant while the latter two were fed with actual dissolved salt in the Savannah River National Laboratory (SRNL) Shielded Cells. Both radioactive cycles ran to cesium breakthrough of the lead column. The resin beds saw in excess of 400 bed volumes of feed in each cycle. Resin disposal plans in tank farm processing depend on characterizations of resin used with actual tank feed. Following a final 30 bed volume (BV) elution with nitric acid, the resin beds were found to contain detectable chromium, barium, boron, aluminum, iron, sodium, sulfur, plutonium, cesium, and mercury. Resin affinity for plutonium is important in criticality safety considerations. Cesium-137 was found to be less than 10E+7 dpm/g of resin, similar to past work with sRF resin. Sulfur levels …

This report describes characterization of a sample obtained from the 3714 building in the 300 Area. Characterization of this unknown material was required for the demonolition activities in the 300 Area. The object of the study was to dertermine the nature of the material, composition, possible structure, evidence for hazards components. The green material is a sodium alumino-silicate glass. This conclusion is based on the composition provided by SEM-EDS, and the images that suggest a glass-like morphology. Further analysis with Ramin and/or infrared could be used to determine the presence of any organics.

The existence of lipid microdomains and their role in cell membrane organization are currently topics of great interest and controversy. The cell membrane is composed of a lipid bilayer with embedded proteins that can flow along the two-dimensional surface defined by the membrane. Microdomains, known as lipid rafts, are believed to play a central role in organizing this fluid system, enabling the cell membrane to carry out essential cellular processes, including protein recruitment and signal transduction. Lipid rafts are also implicated in cell invasion by pathogens, as in the case of the HIV. Therefore, understanding the role of lipid rafts in cell membrane organization not only has broad scientific implications, but also has practical implications for medical therapies. One of the major limitations on lipid organization research has been the inability to directly analyze lipid composition without introducing artifacts and at the relevant length-scales of tens to hundreds of nanometers. Fluorescence microscopy is widely used due to its sensitivity and specificity to the labeled species, but only the labeled components can be observed, fluorophores can alter the behavior of the lipids they label, and the length scales relevant to imaging cell membrane domains are between that probed by fluorescence resonance …

This report discusses the background of cluster munitions in the U.S. military, and the current Department of Defense (DOD) and Obama Administration stances on the topic. It also discusses the two major international initiatives to address cluster munitions: the Convention on Cluster Munitions (CCM) and negotiations under the U.N. Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons (CCW).

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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.

ABSTRACT Initial work focused on the regulation of nitrite reductase, the defining reaction of denitrification as well as nitric oxide (NO) reductase. Expression of the genes encoding both proteins was controlled by NnrR. This regulator was shown to be responsive to NO. More recent work has shown NnrR function is also likely inhibited by oxygen. Therefore, it is this protein that sets the oxygen level at which nitrate respiration takes over from aerobic respiration. The gene encoding NO reductase appears to only require NnrR for expression. Expression of the gene encoding nitrite reductase is more complex. In addition to NnrR, a two component sensor regulator complex termed PrrA and PrrB is also required for expression. These proteins are global regulators and serve to link denitrification with other bioenergetic processes in the cell. They also provide an additional layer of oxygen dependent regulation. The sequencing of the R. sphaeroides 2.4.3 genome allowed us to identify several other genes regulated by NnrR. Surprisingly, most of the genes were not essential for denitrification. Their high level of conservation in related denitrifiers suggests they do provide a selectable benefit to the bacterium, however. We also examined the role of nitrate reductase in contributing to …

This report provides background on free trade areas (FTAs) -- arrangements among two or more countries under which they agree to eliminate tariffs and nontariff barriers on trade in goods among themselves -- why countries form them, and how they relate to U.S. trade policy. It also discusses recent developments, the economic impact of FTAs, the relation of FTAs to the World Trade Organization (WTO) and debate points, as well as general conclusions and implications for Congress.

The effect of various HF-based etching processes on the laser damage resistance of scratched fused silica surfaces has been investigated. Conventionally polished and subsequently scratched fused silica plates were treated by submerging in various HF-based etchants (HF or NH{sub 4}F:HF at various ratios and concentrations) under different process conditions (e.g., agitation frequencies, etch times, rinse conditions, and environmental cleanliness). Subsequently, the laser damage resistance (at 351 or 355 nm) of the treated surface was measured. The laser damage resistance was found to be strongly process dependent and scaled inversely with scratch width. The etching process was optimized to remove or prevent the presence of identified precursors (chemical impurities, fracture surfaces, and silica-based redeposit) known to lead to laser damage initiation. The redeposit precursor was reduced (and hence the damage threshold was increased) by: (1) increasing the SiF{sub 6}{sup 2-} solubility through reduction in the NH4F concentration and impurity cation impurities, and (2) improving the mass transport of reaction product (SiF{sub 6}{sup 2-}) (using high frequency ultrasonic agitation and excessive spray rinsing) away from the etched surface. A 2D finite element crack-etching and rinsing mass transport model (incorporating diffusion and advection) was used to predict reaction product concentration. The predictions are …

Correspondence issued by the Government Accountability Office with an abstract that begins "In 1992, Congress banned schools participating in federal student aid programs from paying commissions, bonuses, or other incentive payments to individuals based on their success in enrolling students or securing financial aid for them. Congress instituted this incentive compensation ban to eliminate abusive recruiting practices in which schools enrolled unqualified students who then received federal student aid funds. In 2002, the U.S. Department of Education (Education) issued regulations--commonly referred to as "safe harbors"--that allowed for 12 activities or payment arrangements that schools could use without violating the ban against incentive compensation. As of January 2010, Education was reviewing these safe harbor regulations as part of a negotiated rule making process to maintain or improve federal student aid programs. The Higher Education Opportunity Act (HEOA) mandated that GAO conduct a study on Education's enforcement of the incentive compensation ban in light of the safe harbors and report on the number of violations substantiated by the Secretary of Education since 1998, the nature of these violations, and the names of the institutions involved. As agreed with Congressional offices, this report provides information on violations of the incentive compensation ban substantiated …

This report discusses congressional interest in the pace of U.S. technological advancement due to its influence on U.S. economic growth, productivity, and international competitiveness. The proper role of the federal government in technology development and the competitiveness of U.S. industry continues to be a topic of congressional debate.

Nonlinear effects are known to occur in Compton scattering light sources, when the laser normalized 4-potential, A = e{radical}-A{sub {mu}}A{sup {mu}}/m{sub 0}c approaches unity. In this letter, it is shown that nonlinear spectral features can appear at arbitrarily low values of A, if the fractional bandwidth of the laser pulse, {Delta}{phi}{sup -1}, is sufficiently small to satisfy A{sup 2} {Delta}{phi} {approx_equal} 1. A three dimensional analysis, based on a local plane-wave, slow-varying envelope approximation, enables the study of these effects for realistic interactions between an electron beam and a laser pulse, and their influence on high-precision Compton scattering light sources.

The threat associated with the potential use of radiological, nuclear, chemical and biological materials in terrorist acts has resulted in new fields of forensic science requiring the application of state-of-the-science analytical techniques. Since the anthrax letter attacks in the United States in the fall of 2001, there has been increased interest in physical and chemical characterization of bacterial spores. While molecular methods are powerful tools for identifying genetic differences, other methods may be able to differentiate genetically identical samples based on physical and chemical properties, as well as provide complimentary information, such as methods of production and approximate date of production. Microanalysis has the potential to contribute significantly to microbial forensics. Bacillus spores are highly structured, consisting of a core, cortex, coat, and in some species, an exosporium. This structure provides a template for constraining elemental abundance differences at the nanometer scale. The primary controls on the distribution of major elements in spores are likely structural and physiological. For example, P and Ca are known to be abundant in the spore core because that is where P-rich nucleic acids and Cadipicolinic acid are located, respectively. Trace elements are known to bind to the spore coat but the controls on these …

We apply ultrafast single shot interferometry to determine the pressure and density of argon shocked from up to 7.8 GPa static initial pressure in a diamond anvil cell. This method enables the observation of thermodynamic states distinct from those observed in either single shock or isothermal compression experiments, and the observation of ultrafast dynamics in shocked materials. We also present a straightforward method for interpreting ultrafast shock wave data which determines the index of refraction at the shock front, and the particle and shock velocities for shock waves in transparent materials. Based on these methods, we observe shocked thermodynamic states between the room temperature isotherm of argon and the shock adiabat of cryogenic argon at final shock pressures up to 28 GPa.

This report discusses Pakistan's efforts to produce fissile material and other issues related to nuclear proliferation and improving its nuclear arsenal. It also discusses the steps Pakistan has taken to increase international confidence in its nuclear security. However, continued instability in Pakistan has caused some to question the effectiveness of its nuclear security reforms. The report addresses these issues as well, in addition to the U.S.-Pakistan relationship as it regards nuclear policy.

We investigate tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides. Resonances are observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors over 103 are possible due to plasmon focusing in the inter-wire space.

A letter report issued by the Government Accountability Office with an abstract that begins "The nation's 4-year not-for-profit colleges and universities collectively held more than $400 billion in endowments in 2008. Some institutions' large endowments coupled with the high and growing cost of college have led to questions about institutions' use of endowments. This mandated report describes (1) the size and change in value of endowments over the last 20 years, (2) the extent and manner to which endowment funds are restricted for financial aid and other purposes, and (3) institutions' distribution of endowment assets. GAO obtained and analyzed data on college and university endowments from the Department of Education and other sources. Because industry-wide data were not available on endowment restrictions and distributions, GAO selected 10 colleges and universities for case studies. The case-study institutions were selected to include a mix of public, private, large, small, and minority-serving institutions. Information from these schools cannot be generalized to all U.S. colleges and universities."

A letter report issued by the Government Accountability Office with an abstract that begins "Following sweeping changes made to federal welfare policy in 1996 with the creation of the Temporary Assistance for Needy Families (TANF) program, the number of needy families who received cash assistance fell by more than half to 1.7 million in 2008. Poverty among children also fell from about 21 percent in 1995 to about 16 percent in 2000, rising again to 19 percent in 2008. The current recession deepened in 2008, raising questions about state TANF programs' response to increased needs. GAO was asked to provide Congress with information on the (1) factors contributing to the decline in the number of families receiving assistance; (2) characteristics of participating and nonparticipating eligible families; (3) impact of higher participation in TANF cash assistance on child poverty; and (4) changes states are experiencing in caseloads and spending in the current recession. GAO's methodologies included using microsimulation analyses; reviewing relevant research and federal laws; interviewing TANF officials in 21 selected states; analyzing state cash assistance data; and interviewing researchers, federal officials, and other experts."

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