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Spectroscopic Abundances And Membership In The Wolf 630 Moving Group, Eric J. Bubar, Jeremy R. King Aug 2010

Spectroscopic Abundances And Membership In The Wolf 630 Moving Group, Eric J. Bubar, Jeremy R. King

Publications

The concept of kinematic assemblages evolving from dispersed stellar clusters has remained contentious since Eggen’s initial formulation of moving groups in the 1960s. With high-quality parallaxes from the Hipparcos space astrometry mission, distance measurements for thousands of nearby, seemingly isolated stars are currently available. With these distances, a high-resolution spectroscopic abundance analysis can be brought to bear on the alleged members of these moving groups. If a structure is a relic of an open cluster, the members can be expected to be monolithic in age and abundance in as much as homogeneity is observed in young open clusters. In this …

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Locating The Accretion Footprint On A Herbig Ae Star: Mwc 480, C A. Grady, K Hamaguchi, G Schneider, B Stecklum, B E. Woodgate, J E. Mccleary, G M. Williger, M L. Sitko, F Menard, Th. Henning, Sean D. Brittain Aug 2010

Locating The Accretion Footprint On A Herbig Ae Star: Mwc 480, C A. Grady, K Hamaguchi, G Schneider, B Stecklum, B E. Woodgate, J E. Mccleary, G M. Williger, M L. Sitko, F Menard, Th. Henning, Sean D. Brittain

Publications

Accretion is a fundamental process which establishes the dynamics of the protoplanetary disk and the final properties of the forming star. In solar-type stars, the star–disk coupling is determined by the magnetic field structure, which is responsible for funneling material from the disk midplane to higher latitudes on the star. Here, we use pan-chromatic data for the Herbig Ae star MWC 480 to address whether similar processes occur in intermediatemass stars. MWC 480 has X-ray emission typical of actively accreting Herbig Ae stars, but with ∼10× more photoelectric absorption than expected from optical and FUV data. We consider three sources …

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Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus Aug 2010

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus

Publications

Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement …

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Elements Of Study On Dynamic Materials, Marine Rousseau, Gerard A. Maugin, Mihhail Berezovski Jul 2010

Elements Of Study On Dynamic Materials, Marine Rousseau, Gerard A. Maugin, Mihhail Berezovski

Publications

As a preliminary study to more complex situations of interest in small-scale technology, this paper envisages the elementary propagation properties of elastic waves in one-spatial dimension when some of the properties (mass density, elasticity) may vary suddenly in space or in time, the second case being of course more original. Combination of the two may be of even greater interest. Toward this goal, a critical examination of what happens to solutions at the crossing of pure space-like and time-like material discontinuities is given together with simple solutions for smooth transitions and numerical simulations in the discontinuous case. The effects on …

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Development Of Daily Precipitation Projections For The United States Based On Probabilistic Downscaling, Justin T. Schoof, Sc Pryor, J Surprenant Jul 2010

Development Of Daily Precipitation Projections For The United States Based On Probabilistic Downscaling, Justin T. Schoof, Sc Pryor, J Surprenant

Publications

No abstract provided.

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The Segmented Electorate: Presidential Campaigns And Their Consequences In An Information Age, Scott D. Mcclurg, Philip Habel Jul 2010

The Segmented Electorate: Presidential Campaigns And Their Consequences In An Information Age, Scott D. Mcclurg, Philip Habel

Publications

It is common to think of presidential elections as long campaigns waged by two warring powers, each competing for the hearts-and-minds of American voters. Yet this metaphor masks considerable variation in how voters experience the campaign in the run-up-to Election Day. We focus on how the rise of candidate-centered campaigns in has created a situation in which some voters experience an avalanche of information from the campaigns and others hear next to nothing. We argue that when we carefully consider which voters should be most responsive to campaign information, that the pattern of segmentation that exists does not advance a …

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Change 2.0, Eric C. Shoaf Jul 2010

Change 2.0, Eric C. Shoaf

Publications

An introduction to the journal is presented in which the author discusses the definition and effects of change, a column by John Lubans on the change that occurs at the close of a professional career, and the value and effectiveness of libraries in an era of increased access to information through the Internet.

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Accelerating Image Feature Comparisons Using Cuda On Commodity Hardware, Amy Apon, Seth Warn, Wesley Emeneker, John Gauch, Jackson Cothren Jul 2010

Accelerating Image Feature Comparisons Using Cuda On Commodity Hardware, Amy Apon, Seth Warn, Wesley Emeneker, John Gauch, Jackson Cothren

Publications

Given multiple images of the same scene, image registration is the process of determining the correct transformation to bring the images into a common coordinate system—i.e., how the images fit together. Feature based registration applies a transformation function to the input images before performing the correlation step. The result of that transformation, also called feature extraction, is a list of significant points in the images, and the registration process will attempt to correlate these points, rather than directly comparing the input images.

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Evidence For The Supernova-Synthesized Dust From The Rising Afterglow Of Grb071025 At Z ∼ 5, Daniel A. Perley, J. S. Bloom, C. R. Klein, S. Covino, T. Minezaki, P. Wozniak, W. T. Vestrand, G. G. Williams, P. Milne, N R. Butler, A C. Updike, T Kruhler, P Afonso, A Antonelli, L Cowie, P Ferrero, J Greiner, Dieter H. Hartmann, Y Kakazu, A Küpcü Yoldaş, A N. Morgan, P A. Price, J X. Prochaska, Y Yoshii Jul 2010

Evidence For The Supernova-Synthesized Dust From The Rising Afterglow Of Grb071025 At Z ∼ 5, Daniel A. Perley, J. S. Bloom, C. R. Klein, S. Covino, T. Minezaki, P. Wozniak, W. T. Vestrand, G. G. Williams, P. Milne, N R. Butler, A C. Updike, T Kruhler, P Afonso, A Antonelli, L Cowie, P Ferrero, J Greiner, Dieter H. Hartmann, Y Kakazu, A Küpcü Yoldaş, A N. Morgan, P A. Price, J X. Prochaska, Y Yoshii

Publications

We present observations and analysis of the broad-band afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < 5.2; at this redshift our simultaneous multicolour observations begin at ∼30 s after the gamma-ray burst trigger in the host frame, during the initial rising phase of the afterglow. We associate the light-curve peak at ∼580 s in the observer frame with the formation of the forward shock, giving an estimate of the initial Lorentz factor 0 ∼ 200. The red spectral energy distribution (even in regions not affected by the Lyman α break) provides secure evidence of a large dust column. However, the inferred extinction curve shows a prominent flat component between 2000 and 3000 Å in the rest frame, inconsistent with any locally observed template but well fitted by models of dust formed by supernovae. Time-dependent fits to the extinction profile reveal no evidence of dust destruction and limit the decrease in the extinction column to A3000 < 0.54 mag after t = 50 s in the rest frame. Together with studies of high-z quasars, our observations suggest a transition in dust properties in the early Universe, possibly associated with a transition between supernova-dominated and asymptotic giant branch-dominated modes of dust production.

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The Customer Isn't Always Right: Limitations Of 'Customer Service' Approaches To Education Or Why Higher Ed Is Not Burger King, Daniel E. Wueste, Teddi Fishman Jul 2010

The Customer Isn't Always Right: Limitations Of 'Customer Service' Approaches To Education Or Why Higher Ed Is Not Burger King, Daniel E. Wueste, Teddi Fishman

Publications

The increasingly popular trend of conceptualising education in terms of 'customer service' is, in some ways, attractive. It encourages educators to think in terms of meeting students' needs and to develop innovative ways to deliver their "product." In other ways, however, it fails to convey the essential collaborative, participatory, reciprocal relationship that is central to effective teaching and learning. With respect to academic integrity, the customer service model also obscures students' roles and responsibilities. In this paper, we identify some of the ways this model provides an inappropriate metaphor for understanding the project of teaching and learning (i.e., education) and …

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Modeling Gas Distribution In Protoplanetary Accretion Disks, Martin Kronberg, Josiah Lewis, Sean D. Brittain Jul 2010

Modeling Gas Distribution In Protoplanetary Accretion Disks, Martin Kronberg, Josiah Lewis, Sean D. Brittain

Publications

Protoplanetary accretion disks are disks of dust and gas which surround and feed material onto a forming star in the earliest stages of its evolution. One of the most useful methods for studying these disks is near infrared spectroscopy of rovibrational CO emission. This paper presents the methods in which synthetically generated spectra are modeled and fit to spectral data gathered from protoplanetary disks. This paper also discussed the methods in which this code can be improved by modifying the code to run a Monte Carlo analysis of best fit across the CONDOR cluster at Clemson University, thereby allowing for …

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Probing Protoplanetary Disk Upper Atmospheres For Heating And Dust Settling Using Synthetic Co Spectra, Josiah Lewis, Martin Kronberg, Sean D. Brittain Jul 2010

Probing Protoplanetary Disk Upper Atmospheres For Heating And Dust Settling Using Synthetic Co Spectra, Josiah Lewis, Martin Kronberg, Sean D. Brittain

Publications

CO emission is a useful probe of the warm gas distribution in the planet forming regions of disks around Herbig Ae/Be (HAeBe) stars. We model UV fluoresced and thermally excited CO in the circumstellar disks of several HAeBes. We find indications of dust settling in the upper atmospheres of HD 141569 and HD 97048 and a correlation between PAH luminosity and gas heating in these two systems.

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Herschel-Pacs Observation Of The 10 Myr Old T Tauri Disk Tw Hya. Constraining The Disk Gas Mass, W F. Thi, G Mathews, F Menard, P Woitke, G Meeus, P Riviere-Marichalar, C Pinte, C D. Howard, A Roberge, G Sandell, I Pascucci, B Riaz, C A. Grady, W.R.F. Dent, I Kamp, G Duchene, J.-C. Augereau, E Pantin, B Vandenbussche, I Tilling, J P. Williams, C Eiroa, D Barrado, J M. Alacid, S Andrews, D R. Ardila, G Aresu, Sean D. Brittain, D R. Ciardi, W Danchi Jul 2010

Herschel-Pacs Observation Of The 10 Myr Old T Tauri Disk Tw Hya. Constraining The Disk Gas Mass, W F. Thi, G Mathews, F Menard, P Woitke, G Meeus, P Riviere-Marichalar, C Pinte, C D. Howard, A Roberge, G Sandell, I Pascucci, B Riaz, C A. Grady, W.R.F. Dent, I Kamp, G Duchene, J.-C. Augereau, E Pantin, B Vandenbussche, I Tilling, J P. Williams, C Eiroa, D Barrado, J M. Alacid, S Andrews, D R. Ardila, G Aresu, Sean D. Brittain, D R. Ciardi, W Danchi

Publications

Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel–PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [O i] and [C ii] as part of the …

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Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain Jul 2010

Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain

Publications

In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 mum, [CII] 157.7 mum, CO 72.8 and 90.2 mum, and o-H2O 78.7 and 179.5 mum. We only detect the [OI] 63.2 …

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A Comparative Analysis Of The Bootstrap Versus Traditional Statistical Procedures Applied To Digital Analysis Based On Benford's Law, Ik Seon Suh, Todd C. Headrick Jul 2010

A Comparative Analysis Of The Bootstrap Versus Traditional Statistical Procedures Applied To Digital Analysis Based On Benford's Law, Ik Seon Suh, Todd C. Headrick

Publications

This study develops a bootstrap procedure applied to digital analysis based on Benford’s Law. It shows that the developed procedure provides accurate diagnoses of fraud as opposed to traditional statistical procedures. The traditional procedures such as the chi-square goodness-of-fit test exhibit the problem of excessive power as the volume of transactions becomes large. This problem may lead auditors to expend unnecessary fraud investigation costs. In contrast, applications of the proposed bootstrap procedure to reported annual earnings of S&P 1500 companies, Federal Election Commission data, and extremely fraudulent data demonstrate the robustness of the proposed procedure over different periods of time …

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Nitrogen Supply And Cyanide Concentration Influence The Enrichment Of Nitrogen From Cyanide In Wheat (Triticum Aestivum L.) And Sorghum (Sorghum Bicolor L.), Stephen Ebbs, Dylan K Kosma, Elizabeth H Nielson, Marylou Machingura, Alan J M Baker, Ian E Woodrow Jul 2010

Nitrogen Supply And Cyanide Concentration Influence The Enrichment Of Nitrogen From Cyanide In Wheat (Triticum Aestivum L.) And Sorghum (Sorghum Bicolor L.), Stephen Ebbs, Dylan K Kosma, Elizabeth H Nielson, Marylou Machingura, Alan J M Baker, Ian E Woodrow

Publications

Cyanide assimilation by the beta-cyanoalanine pathway produces asparagine, aspartate and ammonium, allowing cyanide to serve as alternate or supplemental source of nitrogen. Experiments with wheat and sorghum examined the enrichment of (15)N from cyanide as a function of external cyanide concentration in the presence or absence of nitrate and/or ammonium. Cyanogenic nitrogen became enriched in plant tissues following exposure to (15)N-cyanide concentrations from 5 to 200 microm, but when exposure occurred in the absence of nitrate and ammonium, (15)N enrichment increased significantly in sorghum shoots at solution cyanide concentrations of > or =50 microm and in wheat roots at 200 microm …

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Numerical Studies Of Particle Laden Flow In Dispersed Phase, Shahrdad Sajjadi, Rumma Dutta Jul 2010

Numerical Studies Of Particle Laden Flow In Dispersed Phase, Shahrdad Sajjadi, Rumma Dutta

Publications

To better understand the hydrodynamic flow behavior in turbulence, Particle-Fluid flow have been studied using our Direct Numerical(DNS) based software DSM on MUSCL-QUICK and finite volume algorithm. The particle flow was studied using Eulerian-Eulerian Quasi Brownian Motion(QBM) based approach. The dynamics is shown for various particle sizes which are very relevant to spray mechanism for Industrial applications and Bio medical applications.

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Atmospheric Airglow Fluctuations Due To A Tsunami‐Driven Gravity Wave Disturbance, Michael P. Hickey Ph.D., G. Schubert, R. L. Walterscheid Jun 2010

Atmospheric Airglow Fluctuations Due To A Tsunami‐Driven Gravity Wave Disturbance, Michael P. Hickey Ph.D., G. Schubert, R. L. Walterscheid

Publications

A spectral full‐wave model is used to study the upward propagation of a gravity wave disturbance and its effect on atmospheric nightglow emissions. Gravity waves are generated by a surface displacement that mimics a tsunami having a maximum amplitude of 0.5 m, a characteristic horizontal wavelength of 400 km, and a horizontal phase speed of 200 m/s. The gravity wave disturbance can reach F region altitudes before significant viscous dissipation occurs. The response of the OH Meinel nightglow in the mesopause region (∼87 km altitude) produces relative brightness fluctuations, which are ∼1% of the mean for overhead viewing. The wave …

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On The Ph-Optimum Of Activity And Stability Of Proteins, Kemper Tally, Emil Alexov Jun 2010

On The Ph-Optimum Of Activity And Stability Of Proteins, Kemper Tally, Emil Alexov

Publications

Biological macromolecules evolved to perform their function in specific cellular environment (subcellular compartments or tissues); therefore, they should be adapted to the biophysical characteristics of the corresponding environment, one of them being the characteristic pH. Many macromolecular properties are pH dependent, such as activity and stability. However, only activity is biologically important, while stability may not be crucial for the corresponding reaction. Here, we show that the pH-optimum of activity (the pH of maximal activity) is correlated with the pH-optimum of stability (the pH of maximal stability) on a set of 310 proteins with available experimental data. We speculate that …

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A Geographic Approach To Place And Natural Resource Use In Local Food Systems, Leslie Duram, Lydia Oberholtzer Jun 2010

A Geographic Approach To Place And Natural Resource Use In Local Food Systems, Leslie Duram, Lydia Oberholtzer

Publications

This article illuminates the geographic concept of ‘place’ in local foods. Because the social aspects of local food have been more fully addressed in previous literature, this review focuses instead on the ecological aspects of farming and food. First, the literature on natural resource use in agriculture provides contextual understanding of water use, biodiversity, soils and agro-ecological methods. The complex relationship between climate change and agriculture is described and models assessing the impacts of climate change on agriculture are detailed. The geography of local food is specifically addressed by describing methods for assessing natural resource use in local food, including …

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Visitors From The Halo: 11 Gyr Old White Dwarfs In The Solar Neighborhood, Mukremin Kilic, Ted Von Hippel, Et Al. May 2010

Visitors From The Halo: 11 Gyr Old White Dwarfs In The Solar Neighborhood, Mukremin Kilic, Ted Von Hippel, Et Al.

Publications

We report the discovery of three nearby old halo white dwarf (WD) candidates in the Sloan Digital Sky Survey (SDSS), including two stars in a common proper motion binary system. These candidates are selected from our 2800deg2 proper motion survey on the Bok and U.S. Naval Observatory Flagstaff Station 1.3 m telescopes, and they display proper motions of 0˝.4-0˝.5 yr¯1. Follow-up MMT spectroscopy and near-infrared photometry demonstrate that all three objects are hydrogen-dominated atmosphere WDs with T eff ≈ 3700-4100 K. For average mass WDs, these temperature estimates correspond to cooling ages of 9-10 Gyr, distances of 70-80 pc, and …

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Magnetism And Magnetocaloric Effects In Ni50Mn35−XCoXIn15 Heusler Alloys, Arjun K. Pathak, Igor Dubenko, Christopher Pueblo, Shane Stadler, Naushad Ali May 2010

Magnetism And Magnetocaloric Effects In Ni50Mn35−XCoXIn15 Heusler Alloys, Arjun K. Pathak, Igor Dubenko, Christopher Pueblo, Shane Stadler, Naushad Ali

Publications

The effects of the partial substitution of Mn by Co on the magnetic, magnetoelastic, and magnetocaloric properties of Ni50Mn35In15 Heusler alloys were studied using x-ray diffraction, temperature and field dependences of the magnetization [M(T,H)], and strain gauge techniques. It was observed that the presence of ~3% Co atoms in Mn sites strongly affected the magnetic and magnetoelastic behaviors of Ni50Mn35In15. At H=5 T, a maximum magnetoelastic strain of ~0.6% was observed for Ni50Mn35In15. It was found that Co substituted into the Mn position …

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Co And H+3 Toward Mwc 1080, Mwc 349, And Lkhα 101, E L. Gibb, Sean D. Brittain, T W. Rettig, M Troutman, Theodore Simon, C Kulesa May 2010

Co And H+3 Toward Mwc 1080, Mwc 349, And Lkhα 101, E L. Gibb, Sean D. Brittain, T W. Rettig, M Troutman, Theodore Simon, C Kulesa

Publications

We present high-resolution, near-infrared NIRSPEC observations of the fundamental rovibrational CO and H+ 3 R(1,0), R(1,1) u , and Q(1,0) transitions toward three early-type young stars: MWC 1080, MWC 349, and LkHα 101. These observations were performed for the purpose of constraining the physical characteristics of the interstellar material along each line of sight. Toward MWC 1080, we detected strong CO absorption and determined a column density upper limit of 1.4 × 1014 cm–2 for H+ 3. We infer that there is very little diffuse material along the line of sight toward MWC 1080 and that the CO absorption is …

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Dynamics Groups Of Asynchronous Cellular Automata, Michael Macauley, Jon Mccammond, Henning S. Mortveit May 2010

Dynamics Groups Of Asynchronous Cellular Automata, Michael Macauley, Jon Mccammond, Henning S. Mortveit

Publications

We say that a finite asynchronous cellular automaton (or more generally, any sequential dynamical system) is π-independent if its set of periodic points are independent of the order that the local functions are applied. In this case, the local functions permute the periodic points, and these permutations generate the dynamics group. We have previously shown that exactly 104 of the possible 223 = 256 cellular automaton rules are π-independent. In the article, we classify the periodic states of these systems and describe their dynamics groups, which are quotients of Coxeter groups. The dynamics groups provide information …

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Standardization Of A Volumetric Displacement Measurement For Two-Body Abrasion Scratch Test Data Analysis, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr. May 2010

Standardization Of A Volumetric Displacement Measurement For Two-Body Abrasion Scratch Test Data Analysis, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr.

Publications

A limitation has been identified in the existing test standards used for making controlled, two-body abrasion scratch measurements based solely on the width of the resultant score on the surface of the material. A new, more robust method is proposed for analyzing a surface scratch that takes into account the full three-dimensional profile of the displaced material. To accomplish this, a set of four volume displacement metrics are systematically defined by normalizing the overall surface profile to statistically denote the area of relevance, termed the “Zone of Interaction” (ZOI). From this baseline, depth of the trough and height of the …

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Pulsational Mapping Of Calcium Across The Surface Of A White Dwarf, Susan E. Thompson, Ted Von Hippel, Et Al. May 2010

Pulsational Mapping Of Calcium Across The Surface Of A White Dwarf, Susan E. Thompson, Ted Von Hippel, Et Al.

Publications

We constrain the distribution of calcium across the surface of the white dwarf star G29-38 by combining time-series spectroscopy from Gemini-North with global time-series photometry from the Whole Earth Telescope. G29-38 is actively accreting metals from a known debris disk. Since the metals sink significantly faster than they mix across the surface, any inhomogeneity in the accretion process will appear as an inhomogeneity of the metals on the surface of the star. We measure the flux amplitudes and the calcium equivalent width amplitudes for two large pulsations excited on G29-38 in 2008. The ratio of these amplitudes best fits a …

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Reforming Or Rejecting The Reference Desk: Conflict And Continuity In The Concept Of Reference, David S. Nolen May 2010

Reforming Or Rejecting The Reference Desk: Conflict And Continuity In The Concept Of Reference, David S. Nolen

Publications

This paper contends that the schism between pro- and anti-reference desk librarians is not a true dichotomy. By examining the published literature on the topic, this paper asserts that the two sides actually agree that human-mediation is fundamental to references services, although the articles do examine varying methods for the delivery of reference services. While some emphasize the need to incorporate a more computer-mediated model of reference, most do not truly reject human-mediation as necessary. Those that do fail to provide a satisfactory alternative in the current social and technological context.

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Uaa Student Showcase Journal: Recognizing Excellence (2010), N/A N/A Apr 2010

Uaa Student Showcase Journal: Recognizing Excellence (2010), N/A N/A

Publications

No abstract provided.

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Effect Of Machining Feed On Surface Roughness In Cutting 6061 Aluminum, Mathew Kuttolamadom, Sina Hamzehlouia, Laine Mears Apr 2010

Effect Of Machining Feed On Surface Roughness In Cutting 6061 Aluminum, Mathew Kuttolamadom, Sina Hamzehlouia, Laine Mears

Publications

The general manufacturing objective during the fabrication of automotive components, particularly through machining, can be stated as the striving to achieve predefined product quality characteristics within equipment, cost and time constraints. The current state of the economy and the consequent market pressure has forced vehicle manufacturers to simultaneously reduce operating expenses along with further improving product quality. This paper examines the achievability of surface roughness specifications within efforts to reduce automotive component manufacture cycle time, particularly by changing cutting feeds. First, the background and attractiveness of aluminum as a lightweight automotive material is discussed. Following this, the methodologies employed for …

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Bayesian Estimation Of Mirt Models With General And Specific Latent Traits In Matlab, Yanyan Sheng Apr 2010

Bayesian Estimation Of Mirt Models With General And Specific Latent Traits In Matlab, Yanyan Sheng

Publications

Multidimensional item response models have been developed to incorporate a general trait and several specific trait dimensions. Depending on the structure of these latent traits, different models can be considered. This paper provides the requisite information and description of software that implement the Gibbs sampling procedures for three such models with a normal ogive form. The software developed is written in the MATLAB package IRTm2noHA. The package is flexible enough to allow a user the choice to simulate binary response data with a latent structure involving general and specific traits, specify prior distributions for model parameters, check convergence of the …

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