Browsing by Subject "temperature"

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2006 Texas 303(d) List (June 27, 2007)
(Texas Commission on Environmental Quality, 2007) Texas Commission on Environmental Quality
2008 Texas 303(d) List (March 19, 2008)
(Texas Commission on Environmental Quality, 2008) Texas Commission on Environmental Quality
2010 Texas Integrated Report - Texas 303(d) List (Category 5)
(Texas Commission on Environmental Quality, 2010) Texas Commission on Environmental Quality
2010 Texas Water Quality Inventory: Assessment Results for Basin 14 - Colorado River
(Texas Commission on Environmental Quality, 2010) Texas Commission on Environmental Quality
Algal biofuels : the effect of temperature on algal growth and lipid content
(2009-08) Klenzendorf, Stephanie Marie; Marshall, Jill Ann; Mehdy, Mona Cynthia, 1955-; Sathasivan, Kanagasabapathi
Replacing fossil fuels with algae, a renewable resource, is an exciting possibility. This study evaluates the algae found in South Texas brackish water ponds used for aquaculture of fish as a possible source of biofuels. Samples of algae from these ponds were cultured at varying temperatures ranging from 15.5ºC to 36.5ºC. High levels of growth were observed at 20.5ºC and the highest lipid content was measured at 23.0ºC. Temperature was also a factor in the distribution of microalgal taxa throughout the temperature gradient. This information will be added to the growing body of research investigating similar cultures of algae for future biofuel production.
Before and After Studies on the Effects of a Power Plant Installation on Lake LBJ: A Numerical Temperature Model for Lake LBJ
(University of Texas at Austin, 1971-12) Park, G.G.; Schmidt, P.S.
Before and After Studies on the Effects of a Power Plant Installation on Lake Lyndon B. Johnson: A Numerical Study of the Velocity and Temperature Fields in a Stratified Reservoir with Artificial Thermal Inputs
(University of Texas at Austin, 1974-05) Crow, L.I.; Oberkampf, W.L.
Before and After Studies on the Effects of a Power Plant Installation on Lake Lyndon B. Johnson: Before Studies, Volume III - Temperature Modeling
(University of Texas at Austin, 1975-06) Fruh, E.G.; Maguire, B. Jr; Schmidt, P.S.; Hubbs, C.
Before and After Studies on the Effects of a Power Plant Installation on Lake Lyndon B. Johnson: Some Effects of Temperature on the Population Dynamics of Planktonic Rotifers
(University of Texas at Austin, 1976-06) MacRae, J.R.; Maguire, B. Jr.
The Bolocam Galactic Plane Survey. IX. Data Release 2 and Outer Galaxy Extension
(2013-10) Ginsburg, Adam; Glenn, Jason; Rosolowsky, Erik; Ellsworth-Bowers, Timothy P.; Battersby, Cara; Dunham, Miranda; Merello, Manuel; Shirley, Yancy; Bally, John; Evans, Neal J., II; Stringfellow, Guy; Aguirre, James; Merello, Merello; Evans, Neal J., II
We present a re-reduction and expansion of the Bolocam Galactic Plane Survey (BGPS), first presented by Aguirre et al. and Rosolowsky et al. The BGPS is a 1.1 mm survey of dust emission in the Northern galactic plane, covering longitudes -10 degrees < l < 90 degrees and latitudes vertical bar b vertical bar < 0 degrees.5with a typical 1 sigma rms sensitivity of 30-100 mJy in a similar to 33 '' beam. Version 2 of the survey includes an additional similar to 20 deg(2) of coverage in the third and fourth quadrants and similar to 2 deg(2) in the first quadrant. The new data release has improved angular recovery, with complete recovery out to similar to 80 '' and partial recovery to similar to 300", and reduced negative bowls around bright sources resulting from the atmospheric subtraction process. We resolve the factor of 1.5 flux calibration offset between the v1.0 data release and other data sets and determine that there is no offset between v2.0 and other data sets. The v2.0 pointing accuracy is tested against other surveys and is demonstrated to be accurate and an improvement over v1.0. We present simulations and tests of the pipeline and its properties, including measurements of the pipeline's angular transfer function. The Bolocat cataloging tool was used to extract a new catalog, which includes 8594 sources, with 591 in the expanded regions. We have demonstrated that the Bolocat 40 '' and 80 '' apertures are accurate even in the presence of strong extended background emission. The number of sources is lower than in v1.0, but the amount of flux and area included in identified sources is larger.
Cloning and Expression of R-Spondin1 in Different Vertebrates Suggests a Conserved Role in Ovarian Development
(2008-07) Smith, Craig A.; Shoemaker, Christina M.; Roeszler, Kelly N.; Queen, Joanna; Crews, David; Sinclair, Andrew H.; Shoemaker, Christina M.; Queen, Joanna; Crews, David
R-Spondin1 (Rspo1) is a novel regulator of the Wnt/beta-catenin signalling pathway. Loss-of-function mutations in human RSPO1 cause testicular differentiation in 46, XX females, pointing to a role in ovarian development. Here we report the cloning and comparative expression analysis of R-SPONDIN1 orthologues in the mouse, chicken and red-eared slider turtle, three species with different sex-determining mechanisms. Evidence is presented that this gene is an ancient component of the vertebrate ovary-determining pathway. Results: Gonadal RSPO1 gene expression is female up-regulated in the embryonic gonads in each species at the onset of sexual differentiation. In the mouse gonad, Rspo1 mRNA is expressed in the somatic cell lineage at the time of ovarian differentiation (E12.5-E15.5), with little expression in germ cells. However, the protein is localised in the cytoplasm and at the cell surface of both somatic (pre-follicular) and germ cells. In the chicken embryo, RSPO1 expression becomes elevated in females at the time of ovarian differentiation, coinciding with female-specific activation of the FOXL2 gene and estrogen synthesis. RSPO1 protein in chicken is localised in the outer cortical zone of the developing ovary, the site of primordial follicle formation and germ cell differentiation. Inhibition of estrogen synthesis with a specific aromatase inhibitor results in a decline in chicken RSPO1 expression, indicating that RSPO1 is influenced by estrogen. In the red-eared slider turtle, which exhibits temperature-dependent sex determination, up-regulation of RSPO1 occurs during the temperature-sensitive period, when gonadal development is responsive to temperature. Accordingly, RSPO1 expression is temperature-responsive, and is down-regulated in embryos shifted from female- to male-producing incubation temperatures. Conclusion: These results indicate that RSPO1 is up-regulated in the embryonic gonads of female vertebrates with different sex-determining mechanisms. In all instances, RSPO1 is expressed in the incipient ovary. These findings suggest that R-SPONDIN1 is an ancient, conserved part of the vertebrate ovary-determining pathway.
CMIP5 Climate Model Analyses Climate Extremes in the United States
(2014-04) Wuebbles, Donald; Meehl, Gerald; Hayhoe, Katharine; Karl, Thomas R.; Kunkel, Kenneth; Santer, Benjamin; Wehner, Michael; Colle, Brian; Fischer, Erich M.; Fu, Rong; Goodman, Alex; Janssen, Emily; Kharin, Viatcheslav; Lee, Huikyo; Li, Wenhong; Long, Lindsey N.; Olsen, Seth C.; Pan, Zaitao; Seth, Anji; Sheffield, Justin; Sun, Liqiang; Fu, Rong
Considerations of internal void generation process by observation of melting and solidification behavior in low temperature laser sintering of PEEK
(University of Texas at Austin, 2023) Kigure, T.; Yamauchi, Y.; Ninno, T.
Laser sintering of PEEK performed below the crystallization temperature has been achieved in previous study by low temperature process that anchors the part to a rigid base plate to suppress warpage during processing. However, significant surface roughness and large internal voids are sometimes generated in the parts built by low temperature process, and there are problems in stability of parts quality. The purpose of this study is to contribute to quality improvement of laser sintering of PEEK by low temperature process. It was attempted that clarify the process of surface roughness and void generation by observing the melting and solidification behavior of the material during process with a video camera. From these observation results, it was assumed that the amount of volume change from powder to liquid due to melting and the amount of shrinkage due to solidification affect part quality such as surface roughness and internal voids.
Diel dissolved oxygen patterns and aquatic life use assessment
(City of Austin Watershed Protection Department, 2010) Herrington, Chris; Wagner, Staryn
Diel dissolved oxygen (DO) data from 318 deployments at 38 stream sites were evaluated for spatial and temporal patterns and compared using TCEQ aquatic life use assessment DO criteria versus benthic macroinvertebrate aquatic life use categories. Diel DO data suggest that Austin streams generally maintain high or excellent aquatic life use potential. TCEQ assessment methods may not be appropriate for identifying aquatic life use impairments in some high quality Austin streams, and may yield impairments based on DO that are not observed in benthic macroinvertebrate data. Additional investigation of low DO in Bull Creek preserve lands is needed.
Effects of Nitrogen Photoabsorption Cross Section Resolution on Minor Species Vertical Profiles in Titan's Upper Atmosphere
(2015-03) Luspay-Kuti, A.; Mandt, K. E.; Plessis, S.; Greathouse, T. K.; Plessis, S.
The significant variations in both measured and modeled densities of minor species in Titan's atmosphere call for the evaluation of possible influencing factors in photochemical modeling. The effect of nitrogen photoabsorption cross section selection on the modeled vertical profiles of minor species is analyzed here, with particular focus on C2H6 and HCN. Our results show a clear impact of cross sections used on all neutral and ion species studied. Affected species include neutrals and ions that are not primary photochemical products, including species that do not even contain nitrogen. The results indicate that photochemical models that employ low-resolution cross sections may significantly miscalculate the vertical profiles of minor species. Such differences are expected to have important implications for Titan's overall atmospheric structure and chemistry.
Effects of Temperature on Aqueous Freeform Extrusion Fabrication
(University of Texas at Austin, 2015) Li, Jie; Leu, Ming C.; Hilmas, Gregory E.
An experimental study was conducted to investigate the effect of temperature on ceramic parts produced by paste extrusion based additive manufacturing followed by sintering. A computer-controlled gantry system equipped with a piston extruder was used to extrude aqueous alumina paste. The system includes a temperature control subsystem that allows for freeform extrusion fabrication inside a low-temperature (<0°C) chamber. It can also be used for fabricating parts on a hot plate at ambient or higher temperatures (≥20°C). Test specimens were fabricated from aqueous aluminum pastes at -20°C in the low-temperature chamber and also on the hot plate at 40°C. The minimum angles achievable by these two processes for part fabrication, without use of support material, were compared. Also compared were the relative density and mechanical properties of the parts obtained after sintering. Microstructures were examined via scanning electron microscopy in order to obtain a deeper understanding of the effect of fabrication temperature.
First Results Of The Herschel Key Program >Dust, Ice And Gas In Time> (DIGIT): Dust And Gas Spectroscopy Of HD 100546
(2010) Sturm, B.; Bouwman, J.; Henning, T.; Evans, N. J.; Acke, B.; Mulders, G. D.; Waters, Lbfm; van Dishoeck, E. F.; Meeus, G.; Green, J. D.; Augereau, J. C.; Olofsson, J.; Salyk, C.; Najita, J.; Herczeg, G. J.; van Kempen, T. A.; Kristensen, L. E.; Dominik, C.; Carr, J. S.; Waelkens, C.; Bergin, E.; Blake, G. A.; Brown, J. M.; Chen, J. H.; Cieza, L.; Dunham, M. M.; Glassgold, A.; Gudel, M.; Harvey, P. M.; Hogerheijde, M. R.; Jaffe, D.; Jorgensen, J. K.; Kim, H. J.; Knez, C.; Lacy, J. H.; Lee, J. E.; Maret, S.; Meijerink, R.; Merin, B.; Mundy, L.; Pontoppidan, K. M.; Visser, R.; Yildiz, U. A.; Evans, Neal J.; C. Salyk; Chen, J. H.; Dunham, M. M.; Harvey, P. M.; Jaffe, D.; Kim, H. J.; Lacy, J. H.
Context. We present far-infrared spectroscopic observations, taken with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory, of the protoplanetary disk around the pre-main-sequence star HD 100546. These observations are the first within the DIGIT Herschel key program, which aims to follow the evolution of dust, ice, and gas from young stellar objects still embedded in their parental molecular cloud core, through the final pre-main-sequence phases when the circumstellar disks are dissipated. Aims. Our aim is to improve the constraints on temperature and chemical composition of the crystalline olivines in the disk of HD 100546 and to give an inventory of the gas lines present in its far-infrared spectrum. Methods. The 69 mu m feature is analyzed in terms of position and shape to derive the dust temperature and composition. Furthermore, we detected 32 emission lines from five gaseous species and measured their line fluxes. Results. The 69 mu m emission comes either from dust grains with similar to 70 K at radii larger than 50 AU, as suggested by blackbody fitting, or it arises from similar to 200K dust at similar to 13AU, close to the midplane, as supported by radiative transfer models. We also conclude that the forsterite crystals have few defects and contain at most a few percent iron by mass. Forbidden line emission from [C II] at 157 mu m and [OI] at 63 and 145 mu m, most likely due to photodissociation by stellar photons, is detected. Furthermore, five H(2)O and several OH lines are detected. We also found high-J rotational transition lines of CO, with rotational temperatures of similar to 300K for the transitions up to J = 22-21 and T similar to 800 K for higher transitions.
H2O and OH Gas in the Terrestrial Planet-Forming Zones of Protoplanetary Disks
(2008-03) Salyk, Colette; Pontoppidan, Klaus M.; Blake, Geoffrey A.; Lahuis, Fred; van Dishoeck, Ewine F.; Evans, Neal J., II; Evans, Neal J., II
We present detections of numerous 10-20 mu m H(2)O emission lines from two protoplanetary disks around the T Tauri stars AS 205A and DR Tau, obtained using the InfraRed Spectrograph on the Spitzer Space Telescope. Followup 3-5 mu m Keck NIRSPEC data confirm the presence of abundant water and spectrally resolve the lines. We also detect the P4.5 (2.934 mu m) and P9.5 (3.179 mu m) doublets of OH and (12)CO/(13)CO nu = 1 -> 0 emission in both sources. Line shapes and LTE models suggest that the emission from all three molecules originates between similar to 0.5 and 5 AU, and so will provide a new window for understanding the chemical environment during terrestrial planet Formation. LTE models also imply significant columns of H(2)O and OH in the inner disk atmospheres, suggesting physical transport of volatile ices either vertically or radially, while the significant radial extent of the emission stresses the importance of a more complete understanding of nonthermal excitation processes.
Heat Transfer and Pressure Drop in Heat Exchangers
(University of Texas at Austin, 1938-05-15) University of Texas at Austin
Heat Transfer and Pressure Drop in Heat Exchangers (Revision of Bulletin 3819
(University of Texas at Austin, 1943-06-22) University of Texas at Austin