UT Faculty/Researcher Works

Permanent URI for this collectionhttps://hdl.handle.net/2152/12

University of Texas at Austin faculty and researchers may submit their work to the UT Faculty/Researcher Works collection, by logging in to Texas ScholarWorks with their EID and password. Once you have logged in, please contact the Repository Curator at tsw@utlists.utexas.edu. The Repository Curator will set you up with submission privileges in this collection.

The UT Faculty/Researcher Works collection focuses on electronic research, scholarship, and creative works, as well as materials that primarily reflect the intellectual environment of the UT campus, created by faculty and researchers of the University of Texas at Austin.

Examples of possible content that can be submitted to this collection are:

Peer-reviewed articles where license allows (the Repository Curator can help you determine this)
White papers, working papers and technical reports
Manuscripts
Presentations
Digitized data
Audiovisual material
Any other form of research output that can be technically loaded to the repository.

If you would like more information about the submission process, including alternate submission workflows, please email the Repository Curator at tsw@utlists.utexas.edu

If you have questions about managing your data, please visit the Research Data Services website.

Browse

Now showing 1 - 20 of 3903

1,1 ',1 ''-{ 4-(3,4-Ethylenedioxythiophen-2-Yl)Phenyl Methanetriyl}Tris(1H-Pyraz Ole)
(2011-11) Chen, Xiao-Yan; Yang, Xiaoping; Holliday, Bradley J.; Chen, Xiao-Yan; Yang, Xiaoping; Holliday, Bradley J.
In the title complex, C22H18N6O2S, two of the pyrazole rings are disordered over two sets of sites with ratios of refined occupancies of 0.58 (2):0.42 (2) and 0.517 (12):0.483 (12). The dioxane ring is in a half-chair conformation and the two -CH2-groups of this ring are disordered over two sets of sites, the ratio of refined occupancies being 0.855 (19):0.145 (19). The essentially planar thiophene ring [largest deviation = 0.0444 (2) angstrom] forms a dihedral angle of 19.59 (3)degrees with the benzene ring.
A 12 Minute Orbital Period Detached White Dwarf Eclipsing Binary
(2011-08) Brown, Warren R.; Kilic, Mukremin; Hermes, J. J.; Prieto, Carlos Allende; Kenyon, Scott J.; Winget, D. E.; Hermes, J. J.
We have discovered a detached pair of white dwarfs (WDs) with a 12.75 minute orbital period and a 1315 km s(-1) radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which shows ellipsoidal variations, Doppler boosting, and primary and secondary eclipses. The primary is a 0.25 M-circle dot tidally distorted helium WD, only the second tidally distorted WD known. The unseen secondary is a 0.55 M-circle dot carbon-oxygen WD. The two WDs will come into contact in 0.9 Myr due to loss of energy and angular momentum via gravitational wave radiation. Upon contact the systems may merge (yielding a rapidly spinning massive WD), form a stable interacting binary, or possibly explode as an underluminous Type Ia supernova. The system currently has a gravitational wave strain of 10(-22), about 10,000 times larger than the Hulse-Taylor pulsar; this system would be detected by the proposed Laser Interferometer Space Antenna gravitational wave mission in the first week of operation. This system's rapid change in orbital period will provide a fundamental test of general relativity.
18 Sco: A Solar Twin Rich In Refractory And Neutron-Capture Elements. Implications For Chemical Tagging
(2014-08) Melendez, Jorge; Ramirez, Ivan; Karakas, Amanda I.; Yong, David; Monroe, TalaWanda R.; Bedell, Megan; Bergemann, Maria; Asplund, Martin; Maia, Marcelo Tucci; Bean, Jacob; do Nascimento, Jose-Dias; Bazot, Michael; Alves-Brito, Alan; Freitas, Fabricio C.; Castro, Matthieu; Ramirez, Ivan
We study with unprecedented detail the chemical composition and stellar parameters of the solar twin 18 Sco in a strictly differential sense relative to the Sun. Our study is mainly based on high-resolution (R similar to 110,000), high signal-to-noise ratio (800-1,000) Very Large Telescope UVES spectra, which allow us to achieve a precision of about 0.005 dex in differential abundances. The effective temperature and surface gravity of 18 Sco are T-eff = 5823 +/- 6 K and log g = 4.45 +/- 0.02 dex, i.e., 18 Sco is 46 +/- 6 K hotter than the Sun and log g is 0.01 +/- 0.02 dex higher. Its metallicity is [Fe/H] = 0.054 +/- 0.005 dex, and its microturbulence velocity is +0.02 +/- 0.01 km s-1 higher than solar. Our precise stellar parameters and differential isochrone analysis show that 18 Sco has a mass of 1.04 +/- 0.02 M-circle dot and that it is similar to 1.6 Gyr younger than the Sun. We use precise High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities to search for planets, but none are detected. The chemical abundance pattern of 18 Sco displays a clear trend with condensation temperature, thus showing higher abundances of refractories in 18 Sco than in the Sun. Intriguingly, there are enhancements in the neutron-capture elements relative to the Sun. Despite the small element-to-element abundance differences among nearby n-capture elements (similar to 0.02 dex), we successfully reproduce the r-process pattern in the Solar System. This is independent evidence for the universality of the r process. Our results have important implications for chemical tagging in our Galaxy and nucleosynthesis in general.
1952 Steel Seizure Revisited - Systematic Study In Presidential Decision-Making
(1975-12) Hah, C. D.; Lindquist, R. M.; Lindquist, Robert M.
1st Annual Jackson School Research Symposium
(2012-02-04) Jackson School of Geosciences; The University of Texas at Austin
2 Brothers 1 Wife
(0000-00-00) Hopper, Robert, 1945-1998
2 Guys (Beach - SDCL)
(0000-00-00) Hopper, Robert, 1945-1998
2006 Whole Earth Telescope Observations Of GD358: A New Look At The Prototype DBV
(2009-03) Provencal, J. L.; Montgomery, Michael H.; Kanaan, A.; Shipman, H. L.; Childers, D.; Baran, A.; Kepler, S. O.; Reed, M.; Zhou, A.; Eggen, J.; Watson, T. K.; Winget, D. E.; Thompson, Susan E.; Riaz, B.; Nitta, Atsuko; Kleinman, S. J.; Crowe, R.; Slivkoff, J.; Sherard, P.; Purves, N.; Binder, P.; Knight, R.; Kim, S. L.; Chen, W. P.; Yang, M.; Lin, H. C.; Lin, C. C.; Chen, C. W.; Jiang, X. J.; Sergeev, A. V.; Mkrtichian, D.; Andreev, M.; Janulis, R.; Siwak, M.; Zola, S.; Koziel, D.; Stachowski, G.; Paparo, M.; Bognar, Z.; Handler, G.; Lorenz, D.; Steininger, B.; Beck, P.; Nagel, T.; Kusterer, D.; Hoffman, A.; Reiff, E.; Kowalski, R.; Vauclair, G.; Charpinet, S.; Chevreton, M.; Solheim, J. E.; Pakstiene, E.; Fraga, L.; Dalessio, J.; Montgomery, Michael H.; Winget, D. E.
We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating db white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 mu Hz, with the dominant peak at 1234 mu Hz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l = 1 modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k multiplets is highly suspect. The k = 9 and 8 modes typically do show triplet structure more consistent with theoretical expectations. The frequencies and amplitudes exhibit some variability, but much less than the high-k modes. Analysis of the k = 9 and 8 multiplet splittings from 1990 to 2008 reveal a long-term change in multiplet splittings coinciding with the 1996 sforzando event, where GD358 dramatically altered its pulsation characteristics on a timescale of hours. We explore potential implications, including the possible connections between convection and/or magnetic fields and pulsations. We suggest future investigations, including theoretical investigations of the relationship between magnetic fields, pulsation, growth rates, and convection.
2014 TxETDA Survey of Texas Colleges and Universities
(2015-02-26) Lyon, Colleen; Barba, Shelley; Peterson-Lugo, Billie; Hammons, Laura
2020 TxETDA Survey of Texas Colleges and Universities
(2021-01-13) Barba, Shelley; Lyon, Colleen
2nd Annual Jackson School Research Symposium
(Jackson School of Geosciences, The University of Texas at Austin, 2013-02) The University of Texas at Austin; Jackson School of Geosciences
3-Dimensional Structure Of A Hemichrome Hemoglobin From Caudina arenicola
(1995-09) Mitchell, David T.; Ernst, Stephen R.; Wu, Wei-Xin; Hackert, Marvin L.; Mitchell, David T.; Ernst, Stephen R.; Wu, Wei-Xin; Hackert, Marvin L.
The structure of a monomeric hemichrome form of an invertebrate hemoglobin, Hb-C chain, from Caudina arenicola has been refined to an R value of 0.16 using the data from 5.0 to 2.5 Angstrom resolution (R = 0.21 from 10.0 to 2.5 Angstrom resolution). Hb-C crystallizes in space group P2(1) with cell constants a=45.74, b=45.23 and c=40.92 Angstrom and beta=104.4 degrees with two monomers packed in the unit cell (V-m = 2.34 Angstrom(3) Da(-1)). The phases were determined by the multiple isomorphous replacement method with Hg2+ the major derivative. The structure consists of 157 amino acids with N- and C-terminal regions and eight a-helices forming a heme pocket. The unique feature of this structure is the hemichrome form with the proximal and distal histidines coordinated to the heme Fe atom, which is nearly in the plane of the porphyrin ring. A total of 111 solvent molecules were added to the structure using difference density peaks of at least 3 sigma over background. Interestingly, all the heme groups present in the crystal are nearly coplanar.
3rd Annual Jackson School Research Symposium
(Jackson School of Geosciences, The University of Texas at Austin, 2014-01-25) Jackson School of Geosciences; The University of Texas at Austin
4- Tris(1H-Pyrazol-1-Yl)Methyl Phenol
(2011-11) Chen, Xiao-Yan; Yang, Xiaoping; Holliday, Bradley J.; Chen, Xiao-Yan; Yang, Xiaoping; Holliday, Bradley J.
The title compound, C16H14N6O, was prepared by the condensation of 4-(trifluoromethyl) phenol and sodium pyrazol-1-ide in a yield of 58%. The dihedral angles formed by the planes of the pyrazole rings are 50.7 (2), 71.2 (3) and 95.8 (2)degrees. The molecules are associated into dimers by pairs of intermolecular O-H center dot center dot center dot N hydrogen bonds involving the hydroxy groups and pyrazole N atoms. In addition, pi-pi stacking between the phenol rings of these inversion-related dimers is observed, with a ring centroid-to-centroid distance of 3.9247 (10) angstrom.
4th Annual Jackson School Research Symposium
(2015-02) Jackson School of Geosciences; The University of Texas at Austin
The 69 μm forsterite band in spectra of protoplanetary disks. Results from the Herschel DIGIT programme
(2013-05) Sturm, B.; Bouwman, J.; Henning, T.; Evans, N. J.; Waters, Lbfm; van Dishoeck, E. F.; Green, J. D.; Olofsson, J.; Meeus, G.; Maaskant, K.; Dominik, C.; Augereau, J. C.; Mulders, G. D.; Acke, B.; Merin, B.; Herczeg, G. J.; Digit Team; Evans, Neal J.; Green, J. D.
Context. We have analysed far-infrared spectra of 32 circumstellar disks around Herbig Ae/Be and T Tauri stars obtained within the Herschel key programme Dust, Ice and Gas in Time (DIGIT). The spectra were taken with the Photodetector Array Camera and Spectrometer (PACS) on board the Herschel Space Observatory. In this paper we focus on the detection and analysis of the 69 mu m emission band of the crystalline silicate forsterite. Aims. This work aims at providing an overview of the 69 mu m forsterite bands present in the DIGIT sample. We use characteristics of the emission band (peak position and FWHM) to derive the dust temperature and to constrain the iron content of the crystalline silicates. With this information, constraints can be placed on the spatial distribution of the forsterite in the disk and the formation history of the crystalline grains. Methods. The 69 mu m forsterite emission feature is analysed in terms of position and shape to derive the temperature and composition of the dust by comparison to laboratory spectra of that band. The PACS spectra are combined with existing Spitzer IRS spectra and we compare the presence and strength of the 69 mu m band to the forsterite bands at shorter wavelengths. Results. A total of 32 disk sources have been observed. Out of these 32, 8 sources show a 69 mu m emission feature that can be attributed to forsterite. With the exception of the T Tauri star AS 205, all of the detections are for disks associated with Herbig Ae/Be stars. Most of the forsterite grains that give rise to the 69 mu m bands are found to be warm (similar to 100-200 K) and iron-poor (less than similar to 2% iron). AB Aur is the only source where the emission cannot be fitted with iron-free forsterite requiring approximately 3-4% of iron. Conclusions. Our findings support the hypothesis that the forsterite grains form through an equilibrium condensation process at high temperatures. The large width of the emission band in some sources may indicate the presence of forsterite reservoirs at different temperatures. The connection between the strength of the 69 and 33 mu m bands shows that at least part of the emission in these two bands originates fom the same dust grains. We further find that any model that can explain the PACS and the Spitzer IRS observations must take the effects of a wavelength dependent optical depth into account. We find weak indications of a correlation of the detection rate of the 69 mu m band with the spectral type of the host stars in our sample. However, the sample size is too small to obtain a definitive result.
70 Pages of Change: Improving Queer Representation Online through Strategic Partnerships
(2019-04-12) Bastone, Gina; Covington, Elle
Much of the knowledge developed in online spaces skews to a white, cis-male, heteronormative default, creating significant representational gaps in digital spaces. To tackle these representational inequities, academic librarians and MLS students took digital activism to a new level, partnering with public library and public radio staff to organize two events to address gaps in Wikipedia’s LGBTQIA+ representation. In an initial research event, faculty, staff and students identified missing or inadequate Wikipedia entries and located sources to fill those gaps. The second event put those sources to work in a large-scale Wikipedia edit-a-thon, part of a tech and music festival.
The 8th annual computational and systems neuroscience (Cosyne) meeting
(Neural Systems and Circuits, 2011-04-20) Histed, Mark H.; Pillow, Jonathan W.
The 8th annual Computational and Systems Neuroscience meeting (Cosyne) was held February 24-27, 2011 in Salt Lake City, Utah (abstracts are freely available online: http://www.cosyne.org/c/index.php?title=Cosyne2011_Program webcite). Cosyne brings together experimental and theoretical approaches to systems neuroscience, with the goal of understanding neurons, neural assemblies, and the perceptual, cognitive and behavioral functions they mediate. The range of questions available to systems and computational neuroscience has grown substantially in recent years, with both theoretical and experimental approaches driven by the increasing availability of data about neural circuits and systems. The Cosyne meeting has reflected this growth, nearly doubling in size since the first meeting in 2004, to a new record of nearly 600 attendees this year. It remains single-track, which allows discussions of presentations to drive scientific interaction between attendees with diverse backgrounds. Poster sessions take place each evening, which provide a forum for intense scientific conversations that frequently spill out into more informal settings late at night. The meeting is followed by two days of workshops, held at the Snowbird ski resort, which feature more specialized talks and interactive discussions on a wide collection of topics, this year ranging from consciousness and compressed sensing to dynamics, learning, and perception.
8th Annual Jackson School of Geosciences Student Research Symposium, February 2, 2019
(Jackson School of Geosciences; The University of Texas at Austin, 2019-02) Jackson School of Geosciences; The University of Texas at Austin
9th Annual Jackson School of Geosciences Student Research Symposium, February 15, 2020
(Jackson School of Geosciences; The University of Texas at Austin, 2020-02) Jackson School of Geosciences; The University of Texas at Austin

Browse

Browsing UT Faculty/Researcher Works by Title