Digital Commons Network^™

Growth Of Carbon Grains In Supernova Ejecta, Ethan A-N. Deneault, Donald D. Clayton, Bradley S. Meyer

Publications

We present a chemical reaction network that describes the condensation chemistry of carbon dust grains in an expanding supernova shell. We assume that the region of interest consists solely of gaseous free carbon and oxygen atoms and that the buildup of CO is counteracted by the radioactive decay of 56Co, which breaks up the CO mol-ecule and allows C to condense into solids. Our chemical model takes C to first form linear chains, which, at some critical length, transition into ringed isomers. These isomers are more resistant to oxidation than linear chains. These ringed isomers form the nuclei for the …

The Clock Paradox In A Static Homogeneous Gravitational Field, Preston Jones, Lucas F. Wanex

Publications

The gedanken experiment of the clock paradox is solved exactly using the general relativistic equations for a static homogeneous gravitational field. We demonstrate that the general and special relativistic clock paradox solutions are identical and in particular that they are identical for finite acceleration. Practical expressions are obtained for proper time and coordinate time by using the destination distance as the key observable parameter. This solution provides a formal demonstration of the identity between the special and general relativistic clock paradox with finite acceleration and where proper time is assumed to be the same in both formalisms. By solving the …

Numerical Simulation Of Nonlinear Elastic Wave Propagation In Piecewise Homogeneous Media, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht

Publications

Systematic experimental work [S. Zhuang, G. Ravichandran, D. Grady, J. Mech. Phys. Solids 51 (2003) 245–265] on laminated composites subjected to high velocity impact loading exhibits the dispersed wave field and the oscillatory behavior of waves with respect to a mean value. Such a behavior is absent in homogeneous solids. An approximate solution to the plate impact in layered heterogeneous solids has been developed in [X. Chen, N. Chandra, A.M. Rajendran, Int. J. Solids Struct. 41 (2004) 4635–4659]. The influence of the particle velocity on many process characteristics was demonstrated. Based on earlier results [A. Berezovski, J. Engelbrecht, G.A. Maugin, …

An Evaluation Of Two Gcms: Simulation Of North American Teleconnection Indices And Synoptic Phenomena, Justin T. Schoof, S C. Pryor

Publications

We evaluate the ability of two coupled atmospheric–oceanic GCMs – the Hadley Center’s third generation coupled climate model (HadCM3) and the Canadian Center for Climate Modeling and Analysis second-generation coupled model (CGCM2) – to simulate the North Atlantic Oscillation (NAO), the Pacific North American teleconnection pattern (PNA), and map patterns in the Midwest region of the United States, relative to NCEP/NCAR reanalysis (NNR) data. The observed (NNR-derived) and GCM-derived probability distributions and temporal behavior of the daily teleconnection indices exhibit agreement over the 1990–2001 reference period, and both GCMs successfully reproduce the range of 500-hPa map patterns over the study …

Measurement Of Sediment Oxygen Demand (Sod) In The Royal River Estuary, Yarmouth, Maine, Tim Bridges

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No abstract provided.

Five Good Reasons For Engineering As The Focus For Technology Education, Robert C. Wicklein

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The article presents information on a paper which discusses why engineering design should be the focus for technology education. Technology education is still viewed as a non-essential instructional program and this is because school administrators and counselors have inadequate understanding of it. Even general populace have inadequate understanding concerning technology education. The pervasiveness of technology literally affects every living creature in our society. Therefore, it is of critical importance that the educational system includes and supports the study of technology in the general curricula. The deficiency within the technology education profession to formulate a clear and defined target for the …

Integrating The Study Of Technology Into The Curriculum: A Consulting Teacher Model, Thomas Erekson, Steven Shumway

Publications

Over the past 40 years there have been several initiatives by leaders in the profession to make revolutionary changes in philosophy, curriculum, methods, and facilities in the transition from industrial arts to technology education. The transition to technology education has been grounded in the dramatic changes that technology and technological innovations have brought to all aspects of society. It has been postulated that to fully participate in a technologically-based society, people must be technologically literate (Pearson & Young, 2002). Thus, the need arose to assure that all students have experience in technology education in order to acquire technological literacy.

Logic Circuits And The Quality Of Life, Vincent W. Childress

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The article presents information on the relationship between the logic circuits and the quality of life. The applications of logic circuits are countless. With the flooding of New Orleans in the wake of Hurricane Katrina, people around the world became all too aware of human dependency on technology to manage the forces of nature and maintain a high quality of life. New Orleans' sewage and water control systems depend on water pumps to move sewage, storm-water runoff, and fresh water around the city. Under normal conditions, when it rains in New Orleans, a city that sits below sea level, massive …

Creativity: A Framework For The Design/Problem Solving Discourse In Technology Education, Theodore Lewis

Publications

Subjects for which aesthetics and creative performance are critical curricular dimensions (such as art, physical education, music, and technology education), and which are accommodative of students across the range of intelligences (Gardner, 1999) are not readily or completely captured by content standards. Therefore content knowledge in these fields that target student achievement as conventionally conceived must be complemented by treatment of more subjective and elusive goals such as the development of connoisseurship, appreciation, or creative insight. With the publication of standards for the subject (International Technology Education Association, 2000), the need for focus upon creativity in technology education has been …

New Perspectives: Technology Teacher Education And Engineering Design, Roger B. Hill

Publications

Initiatives to integrate engineering design within the field of technology education are increasingly evident (Lewis, 2005; Wicklein, 2006). Alliances between technology education and engineering were prominent in the development of the Standards for Technological Literacy (International Technology Education Association, 2000), and leaders from both disciplines have expressed support for the outcomes described in the Standards (Bybee, 2000; Council of the National Academy of Engineering, 2000; Dugger, Meade, Delany, and Nichols, 2003; Gorham, Newberry, and Bickart, 2003). The National Science Foundation (NSF) has also encouraged and funded opportunities for technology educators and engineers to work collaboratively. The Bridges for Engineering Education …

Radioactive 26al And Massive Stars In The Galaxy, Roland Diehl, Hubert Halloin, Karsten Kretschmer, Giselher G. Lichiti, Volker Schönfelder, Andrew W. Strong, Andreas Von Kienlin, Wei Wang, Pierre Jean, Jürgen Knödlseder, Jean-Pierre Roques, Georg Weidenspointner, Stephane Schanne, Dieter H. Hartmann, Christoph Winkler, Cornelia Wunderer

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Gamma-rays from radioactive 26Al (half life ~7.2 105 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy1. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane of the Galaxy2. This led to the conclusion1 that massive stars throughout the Galaxy dominate the production of 26Al. On the other hand, meteoritic data show locally-produced 26Al, perhaps from spallation reactions in the protosolar disk. Furthermore, prominent gamma-ray emission from the Cygnus region2,3 suggests that a substantial fraction of Galactic 26Al could originate in localized star-forming regions. Here we report high spectral resolution …

Cognitive Engineering Research Methodology: A Proposed Study Of Visualization Analysis Techniques, Cristin M. Hall, Sonya A.H. Mcmullen, David L. Hall

Publications

The rapid development of new sensors and wide-band communications provides the capability to collect enormous amounts of data. An increasing challenge involves how to understand and interpret the data to yield knowledge about evolving situations or threats (e.g., of military situations, state of complex systems, etc.). New visualization tools and techniques are becoming available to support advanced visualization including three-dimensional, full immersion display environments and tools to support novel visualizations. Examples include network system display tools and evolving multi-sensory situation environments. Despite the emergence of such tools, there has been limited systematic test and evaluations to determine the efficacy of …

Assessing Trace Evidence Left By Secure Deletion Programs, Paul Burke, Philip Craiger

Publications

Secure deletion programs purport to permanently erase files from digital media. These programs are used by businesses and individuals to remove sensitive information from media, and by criminals to remove evidence of the tools or fruits of illegal activities. This paper focuses on the trace evidence left by secure deletion programs. In particular, five Windows-based secure deletion programs are tested to determine if they leave identifiable signatures after deleting a file. The results show that the majority of the programs leave identifiable signatures. Moreover, some of the programs do not completely erase file metadata, which enables forensic investigators to extract …

Tax Strategies Are Not Patentable Inventions, Andrew A. Schwartz

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No abstract provided.

Transfer Of Training From Flight Training Devices To Flight For Ab-Initio Pilots, Nickolas D. Macchiarella, Pamela K. Arban, Shawn M. Doherty

Publications

The application of flight simulation to meet pilot training needs continues to evolve. Flight simulations built with powerful and inexpensive computers are making high fidelity simulation available as a medium for training ab-initio pilots at Pilot Schools and Training Centers. The researchers conducted an 18-month study that applied an experimental flight-training curriculum comprised of 60% flight training device (FTD) flight and 40% airplane flight to certify Private Pilots under Federal Aviation Regulation (FAR) Part 142. The results from the research provided data to ascertain the effective transfer for each flight-training task. Ab-initio student pilots practiced each task to standard in …

Academic Freedom: Disciplinary Lessons From Hogwarts, Emily M. Calhoun

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No abstract provided.

The Next Epidemic: Bubbles And The Growth And Decay Of Securities Regulation, Erik F. Gerding

Publications

This article explores how speculative bubbles undermine the effectiveness of securities regulations and spawn epidemics of securities fraud. A brief historical survey demonstrates that stock market bubbles almost invariably coincide with epidemics of securities fraud, and provides a compelling argument that the outbreak of fraud in the Enron era did not stem merely from factors unique to the 1990s, but from the dynamics of an asset price bubble as well.

Drawing on perspectives from securities law practice and economic theory, the article argues that bubbles dilute the deterrent effect of antifraud rules and promote deregulation. Both effects alter the calculus …

The Unexpected Value Of Litigation: A Real Options Perspective, Joseph A. Grundfest, Peter H. Huang

Publications

In this Article, we suggest that litigation can be analyzed as though it is a competitive research and development project. Developing this analogy, we present a two-stage real option model of the litigation process that involves sequential information revelation and bargaining over the surplus generated by early settlement. Litigants are risk-neutral and have no private information. The model generates results that, we believe, have analytic and normative significance for the economic analysis of litigation

From an analytic perspective, we demonstrate that negative expected value (NEV) lawsuits are analogous to out of the money call options held by plaintiffs and that …

Against "Academic Deference": How Recent Developments In Employment Discrimination Law Undercut An Already Dubious Doctrine, Scott A. Moss

Publications

When the defendant in an employment case is a college or other institution of higher education, the plaintiff usually will face an "academic deference" argument. Citing the importance of their "academic freedom," defendants and sympathetic courts have asserted that federal courts should decline to "invade" higher education with "federal court supervision." Whether or not courts cite the "academic deference" doctrine expressly, they certainly have proven hostile to professors' claims of discrimination, dismissing as a matter of law claims that seemed quite strong, or at least solid enough to allow a factfinder to rule either way. Indeed, empirical evidence shows that …

Observations Of Triboelectric Charging Effects On Langmuir-Type Probes In Dusty Plasma, Aroh Barjatya, Charles M. Swenson

Publications

Investigation of Earth’s mesosphere using sounding rockets equipped with a myriad of instruments has been a highly active field in the last 2 decades. This paper presents data from three separate instruments: an RF impedance probe, a DC fixed bias Langmuir probe, and an electric field probe, that were flown on a mesospheric sounding rocket flight investigating the presence of charged dust within and/or around a sporadic metal layer. The combined data set indicates a case of payload surface charging, the causes of which are investigated within this paper. A generic circuit model is developed to analyze payload charging and …

Cool White Dwarfs In The Sloan Digital Sky Survey, Mukremin Kilic, Jeffrey A. Munn, Hugh C. Harris, James W. Liebert, Ted Von Hippel, Kurtis A. Williams, Travis S. Metcalfe, D. E. Winget, Stephen E. Levine

Publications

A reduced proper motion diagram utilizing Sloan Digital Sky Survey (SDSS) photometry and astrometry and USNO-B plate astrometry is used to separate cool white dwarf candidates from metal-weak, high-velocity, mainsequence Population II stars (subdwarfs) in the SDSS Data Release 2 imaging area. Follow-up spectroscopy using the Hobby-Eberly Telescope, the MMT, and the McDonald 2.7 m telescope is used to demonstrate that the white dwarf and subdwarf loci separate cleanly in the reduced proper motion diagram and that the contamination by subdwarfs is small near the cool white dwarf locus. This enables large, statistically complete samples of white dwarfs, particularly the …

The White Dwarf Luminosity Function From Sloan Digital Sky Survey Imaging Data, Hugh C. Harris, Jeffrey A. Munn, Mukremin Kilic, James W. Liebert, Kurtis A. Williams, Ted Von Hippel, Stephen E. Levine, David G. Monet, Daniel J. Eisenstein, S. J. Kleinman, T. S. Metcalfe, Atsuko Nikka, D. E. Winget, J. Brinkmann, Masataka Fukugita, G. R. Knapp, Robert H. Lupton, J. Allyn Smith, Donald P. Schneider

Publications

A sample of white dwarfs is selected from the Sloan Digital Sky Survey (SDSS) Data Release 3 using their reduced proper motions, based on improved proper motions from combined SDSS and USNO-B data. Numerous SDSS and follow-up spectra (Kilic and coworkers) are used to quantify completeness and contamination of the sample; kinematicsmodels are used to understand and correct for velocity-dependent selection biases.A luminosity function is constructed covering the range 7 < Mbol < 16, and its sensitivity to various assumptions and selection limits is discussed. The white dwarf luminosity function based on 6000 stars is remarkably smooth and rises nearly monotonically to Mbol=15.3. It then drops abruptly, although the small number of low-luminosity stars in the sample and their unknown atmospheric composition prevent quantitative conclusions about this decline. Stars …

Book Review: The Amateur Astronomer's Introduction To The Celestial Sphere, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Amateur Astronomer's Introduction to the Celestial Sphere by William Millar. Cambridge, 2006 299p, 052167123X $40.00, 9780521671231 $40.00.

Research-Based Web Design & Usability Guidelines [2006 Edition], Michael O. Leavitt, Ben Shneiderman, Robert W. Bailey, Carol Barnum, John Bosley, Barbara Chaparro, Joseph Dumas, Melody Y. Ivory, Bonnie John, Hal Miller-Jacobs, Sanjay J. Koyani, James R. Lewis, Stanley Page, Judith Ramey, Janice (Ginny) Redish, Jean Scholtz, Steve Wigginton, Cari A. Wolfson, Larry E. Wood, Don Zimmerman

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The new edition of the U.S. Department of Health and Human Services’ (HHS) Research-Based Web Design and Usability Guidelines. These guidelines reflect HHS’ commitment to identifying innovative, research-based approaches that result in highly responsive and easy-to-use Web sites for the public.

These guidelines help move us in that direction by providing practical, yet authoritative, guidance on a broad range of Web design and communication issues. Having access to the best available research helps to ensure we make the right decisions the first time around and reduces the possibility of errors and costly mistakes.

On Doubly Periodic Solutions Of Quasilinear Hyperbolic Equations Of The Fourth Order, T. Kiguradze, T. Smith

Publications

The problem on doubly periodic solutions is considered for a class of quasilinear hyperbolic equations. Effective sufficient conditions of solvability and unique solvability of this problem are established.

Rocket And Radar Investigation Of Background Electrodynamics And Bottom-Type Scattering Layers At The Onset Of Equatorial Spread F, D. L. Hysell, M. F. Larsen, C. M. Swenson, A. Barjatya, T. F. Wheeler, T. W. Bullett, Et. Al.

Publications

Sounding rocket experiments were conducted during the NASA EQUIS II campaign on Kwajalein Atoll designed to elucidate the electrodynamics and layer structure of the postsunset equatorial F region ionosphere prior to the onset of equatorial spread F (ESF). Experiments took place on 7 and 15 August 2004, each comprised of the launch of an instrumented and two chemical release sounding rockets. The instrumented rockets measured plasma number density, vector electric fields, and other parameters to an apogee of about 450 km. The chemical release rockets deployed trails of trimethyl aluminum (TMA) which yielded wind profile measurements. The Altair radar was …

The Dust Cloud Around The White Dwarf G29-38, William T. Reach, Ted Von Hippel, Et Al.

Publications

We present new observations of the white dwarf G29-38 with the camera (4.5 and 8 μm), photometer (24 μm), and spectrograph (5.5-14 μm) of the Spitzer Space Telescope. This star has an exceptionally large infrared excess, amounting to 3% of the bolometric luminosity. The spectral energy distribution (SED) has a continuum peak around 4.5 μm and a 9-11 μm emission feature 1.25 times brighter than the continuum. A mixture of amorphous olivine and a small amount of forsterite in an emitting region 1-5 R☉ from the star can reproduce the shape of the 9-11 μm feature. The SED …

A Multisite Photometric Campaign On The Pre-Main-Sequence ₰ Delta Scuti Pulsator Ip Per, V. Ripepi, T. D. Oswalt, S. Bernabei, M. Marconi, Et Al.

Publications

We present the results of a photometric multisite campaign on the δ Scuti Pre-Main-Sequence star IP Per. Nine telescopes have been involved in the observations, with a total of about 190 h of observations over 38 nights. Present data confirms the multiperiodic nature of this star and leads to the identification of at least nine pulsational frequencies. Comparison with the predictions of linear non-adiabatic radial pulsation models allowed us to identify only five of the nine observed frequencies, and to constrain the position of IP Per in the HR diagram. The latter is in good agreement with the empirical determination …

Limited Dispersal And Heterogeneous Predation Risk Synergistically Enhance Persistence Of Rare Prey, Brett J. Goodwin, Clive G. Jones, Eric M. Schauber, Richard S. Ostfeld

Publications

White-footed mice prey on gypsy moth pupae while foraging for other, more abundant food. Mice appear capable of locally extirpating moths since mice exert high predation pressure on sparse pupae and are numerically decoupled from moth populations. Nevertheless, during 23 years of monitoring, moths persisted at scales .1 ha despite frequent extinctions at smaller spatial scales. We hypothesized that spatially heterogeneous intensity in mouse foraging and/or limited moth dispersal might allow moth persistence. Using a spatially explicit, individual-based, empirically parameterized model, we show that neither spatially heterogeneous predation by mice, nor limited moth dispersal alone allows moth persistence at typical …

Measuring The Evolution Of The Most Stable Optical Clock G 117-B15a, S. O. Kepler, Ted Von Hippel, Et Al.

Publications

We report our measurement of the rate of change of period with time () for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4 σ measurement observed = (4.27 ± 0.80) × 10-15 s s-1. Taking into account the proper-motion effect of proper = (7.0 ± 2.0) × 10-16s s-1, we obtain a rate of change of period with time of = (3.57 ± 0.82) × 10-15 s s-1. This value is consistent with the cooling rate in our white dwarf …