Measurement of Momentum Transfer Coefficients for H2, N2, CO, and CO2 Incident Upon Spacecraft Surfaces

Measurements of momentum transfer coefficients were made for gas-surface interactions between the Space Shuttle reaction control jet plume gases and the solar panel array materials to be used on the International Space Station. Actual conditions were simulated using a supersonic nozzle source to produce beams of the gases with approximately the same average velocities as the gases have in the Shuttle plumes. Samples of the actual solar panel materials were mounted on a torsion balance that was used to measure the force exerted on the surfaces by the molecular beams. Measurements were made with H2, N2, CO, and CO2 incident upon the solar array material, Kapton, SiO2-coated Kapton, and Z93-coated Al. The measurements showed that molecules scatter from the surfaces more specularly as the angle of incidence increases and that the scattering behavior has a strong dependence upon both the incident gas and velocity. These results show that for some technical surfaces the simple assumption of diffuse scattering with complete thermal accommodation is entirely inadequate. It is clear that additional measurements are required to produce models that more accurately describe the gas-surface interactions encountered in rarefied flow regimes

Simulated binding of transcription factors to active and inactive regions folds human chromosomes into loops, rosettes and topological domains

Biophysicists are modeling conformations of interphase chromosomes, often basing the strengths of interactions between segments distant on the genetic map on contact frequencies determined experimentally. Here, instead, we develop a fitting-free, minimal model: bivalent or multivalent red and green 'transcription factors' bind to cognate sites in strings of beads ('chromatin') to form molecular bridges stabilizing loops. In the absence of additional explicit forces, molecular dynamic simulations reveal that bound factors spontaneously cluster-red with red, green with green, but rarely red with green-to give structures reminiscent of transcription factories. Binding of just two transcription factors (or proteins) to active and inactive regions of human chromosomes yields rosettes, topological domains and contact maps much like those seen experimentally. This emergent 'bridging-induced attraction' proves to be a robust, simple and generic force able to organize interphase chromosomes at all scales

The Arts as a Teaching Tool and the Power of Collaboration and Co-teaching

Over the last seventeen years, an arts education initiative has transformed the dynamics of an isolated rural school into a model for rural arts access. Three teachers from Copper Basin High School began an avalanche of possibilities in 1997 when the Annenberg Rural Challenge Grant provided funding to begin a new era in a small rural school. Isolated by geographical boundaries and stifled by economical hardships since the closing of the copper mines in 1988, something had to be done. After a series of teacher in-services for visual strategies (using art as a teaching tool reflective of Gardner\u27s Multiple Intelligences), followed with collaborations between teachers and art consultants, students were led to a deeper understanding through problem solving, critical thinking, and creative explorations. After this experiment proved successful, in a grassroots self-supporting survival move, a non-profit organization was established and grants were obtained to continue and expand the work. In 2004, an unexpected corporate partnership with Glenn Springs Holdings, Inc. was established to provide funding and support to develop the Copper Basin Learning Center. This session examines the path that led to the Learning Center, challenges faced along the way, and what works in the program and why. There is a lot of talk on the educational forefront today concerning moving from STEM to STEAM, with the arts being a significant component. Discussion will include dispelling basic assumptions and developing a workable plan of action for incorporating the arts in the school curriculum

Higher-order-in-spin interaction Hamiltonians for binary black holes from source terms of Kerr geometry in approximate ADM coordinates

The Kerr metric outside the ergosphere is transformed into ADM coordinates up to the orders $1/r^4$ and $a^2$, respectively in radial coordinate $r$ and reduced angular momentum variable $a$, starting from the Kerr solution in quasi-isotropic as well as harmonic coordinates. The distributional source terms for the approximate solution are calculated. To leading order in linear momenta, higher-order-in-spin interaction Hamiltonians for black-hole binaries are derived.Comment: REVTeX4, 20 pages, typos corrected in Eq. (124) and (130

Wound Botulism in Injection Drug Users: Time to Antitoxin Correlates with Intensive Care Unit Length of Stay

Objectives: We sought to identify factors associated with need for mechanical ventilation (MV), length of intensive care unit (ICU) stay, length of hospital stay, and poor outcome in injection drug users (IDUs) with wound botulism (WB).Methods: This is a retrospective review of WB patients admitted between 1991-2005. IDUs were included if they had symptoms of WB and diagnostic confirmation. Primary outcome variables were the need for MV, length of ICU stay, length of hospital stay, hospital-related complications, and death.Results: Twenty-nine patients met inclusion criteria. Twenty-two (76%) admitted to heroin use only and seven (24%) admitted to heroin and methamphetamine use. Chief complaints on initial presentation included visual changes, 13 (45%); weakness, nine (31%); and difficulty swallowing, seven (24%). Skin wounds were documented in 22 (76%). Twenty-one (72%) patients underwent mechanical ventilation (MV). Antitoxin (AT) was administered to 26 (90%) patients but only two received antitoxin in the emergency department (ED). The time from ED presentation to AT administration was associated with increased length of ICU stay (Regression coefficient = 2.5; 95% CI 0.45, 4.5). The time from ED presentation to wound drainage was also associated with increased length of ICU stay (Regression coefficient = 13.7; 95% CI = 2.3, 25.2). There was no relationship between time to antibiotic administration and length of ICU stay.Conclusion: MV and prolonged ICU stays are common in patients identified with WB. Early AT administration and wound drainage are recommended as these measures may decrease ICU length of stay.[West J Emerg Med. 2009;10(4):251-256.

Water System Consolidation for Westinghouse Savannah River Company

Proceedings of the 1995 Georgia Water Resources Conference, April 11 and 12, 1995, Athens, Georgia.As part of a water distribution study for Westinghouse Savannah River Company (WSRC), Metcalf & Eddy, Inc. (M&E) evaluated the potential for total or partial consolidation of the site's water supply systems. Under current operation, the site meets water demand through 28 systems serving populations from 1000 to 6000 consumers. With an overall 24-hour average water demand of 1080 gallons per minute (gpm) and peak water demands varying in each system from 10 to 750 gpm, the site area for consolidation covers approximately 300 square miles. Multiple consolidation alternatives were evaluated for consolidation of the drinking water supply. Potential shifts in population centers and area demands was an important element considered in the study. The evaluation of the alternatives considered available groundwater and surface water quality and quantity to meet the projected demand while considering capital costs, operational reliability and flexibility, and low life-cycle cost. Hydraulic analysis of the water distribution transmission lines for each alternative were modelled using an M&E digital computer modeling program. Ranking and weighting of both economic and non-economic factors allowed for a recommendation of a final alternative for consolidation. It was shown that in many cases, non-economic factors could be as important, if not more important, than economic factors.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Carl Vinson Institute of Government, The University of Georgia, Athens, Georgia 30602 with partial funding provided by the U.S. Department of Interior, Geological Survey, through the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors

Computation in Classical Mechanics

There is a growing consensus that physics majors need to learn computational skills, but many departments are still devoid of computation in their physics curriculum. Some departments may lack the resources or commitment to create a dedicated course or program in computational physics. One way around this difficulty is to include computation in a standard upper-level physics course. An intermediate classical mechanics course is particularly well suited for including computation. We discuss the ways we have used computation in our classical mechanics courses, focusing on how computational work can improve students' understanding of physics as well as their computational skills. We present examples of computational problems that serve these two purposes. In addition, we provide information about resources for instructors who would like to include computation in their courses.Comment: 6 pages, 3 figures, submitted to American Journal of Physic

Recent Decisions

Recent Decisions Admiralty--Time Charter--Shipowner\u27s Contractual Right to Withdraw Services of Vessel upon Charterer\u27s Failure to Provide Punctual Payment is not Extinguished by Late Tender of Payment Richard F. Cook, Jr. =========================== Antitrust--Treble Damages--A Foreign Sovereign is a Person entitled to Sue under Section 4 of the Clayton Act Edward Cage Brewer, III ========================== Customs search of International Mail--A Customs Search of International Mail is Authorized by 19 C.F.R. § 145.2 and Incorporates the Reasonable Cause to Suspect Requirement of 19 U.S.C. § 482 Daniel R. Wofsey =========================== Jurisdiction and Procedure--Discovery--Party unable to comply with Discovery Order which Contravenes Foreign Nondisclosure Law is not in Contempt of Court Sue D. Sheridan =========================== Treaties--Drugs and Narcotics--Single Convention on Narcotic Drugs permits the United States to Place fewer Restrictions on Separated Marijuana Leaves Steven M. Morga