Parabolic Trough Receiver Heat Loss Testing (Poster)

Parabolic trough receivers, or heat collection elements (HCEs), absorb sunlight focused by the mirrors and transfer that thermal energy to a fluid flowing within them. Thje absorbing tube of these receivers typically operates around 400 C (752 F). HCE manufacturers prevent thermal loss from the absorbing tube to the environment by using sputtered selective Cermet coatings on the absorber and by surrounding the absorber with a glass-enclosed evacuated annulus. This work quantifies the heat loss of the Solel UVAC2 and Schott PTR70 HCEs. At 400 C, the HCEs perform similarly, losing about 400 W/m of HCE length. To put this in perspective, the incident beam radiation on a 5 m mirror aperture is about 4500 W/m, with about 75% of that energy ({approx} 3400 W/m) reaching the absorber surface. Of the 3400 W/m on the absorber, about 3000 W/m is absorbed into the working fluid while 400 W/m is lost to the environment.
Date: March 1, 2007
Creator: Price, H.; Netter, J.; Bingham, C.; Kutscher, C.; Burkholder, F. & Brandemuehl, M.
System: The UNT Digital Library

Go For Breakfast, Go For Gold

A poster advertising the school breakfast week Olympics, March 5-9th.
Date: [2007-01-04..2014-11-16]
Creator: Texas. Department of Agriculture.
System: The Portal to Texas History

My Plate. My Tray. My Health.

This document provides information on how to divide ones plate or tray healthily.
Date: [2007-01..2014-11]
Creator: Texas. Department of Agriculture.
System: The Portal to Texas History

The new D0 layer 0 silicaon detector

None
Date: June 1, 2006
Creator: Strom, Derek A.
System: The UNT Digital Library

The Wind/Water Nexus

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Date: June 1, 2006
Creator: Flowers, Laura
System: The UNT Digital Library

Photon and neutron productions studies in the MIPP experiment

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Date: May 1, 2006
Creator: Nigmanov, Turgun
System: The UNT Digital Library

Center for Environmental Kinetics Analysis

Over the past two decades, numerous studies have produced high quality information on the rates at which bacteria can reduce metal oxides. The prototypical study--such as the one depicted to the right--focuses on only a few of the myriad variables affecting the rate. This approach allows for effective dissection of the mechanisms underlying DMRB activity, but, it also produces disjoint information that must be synthesized if we hope to predict the behavior of bacteria at the systems level.
Date: April 5, 2006
Creator: Bandstra, Joel Z.; Burgos, William D. & Peyton, Brent M.
System: The UNT Digital Library

Kinetics of U(VI) reduction control kinetics of U(IV) reoxidation

For the in situ reductive immobilization of U to be an acceptable strategy for the removal of that element from groundwater, the long-term stability of U(IV) must be determined. Rates of biotransformation of Fe species influence the mineralogy of the resulting products (Fredrickson et al., 2003; Senko et al., 2005), and we hypothesize that the rate of U(VI) reduction influences the mineralogy of resultant U(IV) precipitates. We hypothesize that slower rates of U(VI) reduction will yield U(IV) phases that are more resistant to reoxidation, and will therefore be more stable upon cessation of electron donor addition. U(IV) phases formed by relatively slow reduction may be more crystalline or larger in comparison to their relatively rapidly-formed counterparts (Figure 1), thus limiting the reactivity of slowly-formed U(IV) phases toward various oxidants. The physical location of U(IV) precipitates relative to bacterial cells may also limit the reactivity of biogenic U(IV) phases. In this situation, we expect that precipitation of U(IV) within the bacterial cell may protect U(IV) from reoxidation by limiting physical contact between U(IV) and oxidants (Figure 1). We assessed the effect of U(VI) reduction rate on the subsequent reoxidation of biogenic U(IV) and are currently conducting column scale studies to determine …
Date: April 5, 2006
Creator: Senko, J.M.; Minyard, M.L.; Dempsey, B.A.; Roden, E.E.; Yeh, G.-T. & Burgos, W.D.
System: The UNT Digital Library

Testing the Concept of Drift Shadow Using X-Ray Absorption Imaging

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Date: November 22, 2005
Creator: Forsberg, A. A.; Altman, S. J.; Peplinski, W. J. & Ho, C. K.
System: The UNT Digital Library

Anisotropic Flow in the Forward Directions

The STAR Forward TPCs (FTPCs) extend the STAR acceptance for charged particles into the region 2.5 < |eta| < 4.0. We see the first signal of directed flow (v{sub 1}) at RHIC energies. While v{sub 1} is consistent with zero in the central rapidity region it rises up to 2 percent at pseudorapidities of +-4. With this signal we can verify that elliptic flow (v{sub 2}) is in-plane. The measurement of v{sub 2} in the FTPCs confirms the falloff by a factor of about 2 compared to mid-rapidity previously seen by PHOBOS [1]. In addition we look for higher harmonics (v{sub n}, n>2) where in the case of v{sub 4} a signal is seen in the STAR TPC. With the available statistics for the FTPCs we give an upper limit for these harmonics, since the results agree with zero within the errors. However, the falloff of v{sub 4} from mid-rapidity to forward-rapidities appears to be faster than for v{sub 2}.[1] B.B. Back. Phys. Rev. Lett. 89, 222301 (2002)
Date: March 9, 2004
Creator: Oldenburg, Markus D. & Putschke, Jorn
System: The UNT Digital Library

Ecoregions of Texas [Poster]

Poster containing a map color-coded to "denote areas of general similarity in ecosystems and in the type, quality and quantity of environmental resources" with a key to regions and sub-regions in the lower-left corner along with a similar inset for the conterminous United States (scale 1:2,500,000). The poster also includes a list of the regions in Texas with descriptions and illustrative photographs to the right of the map, which is continued on the back. The back of the poster also includes a smaller version of the state map in the lower-left corner along with a list of common and scientific names of native plants and and wildlife, as well as a source list.
Date: 2004
Creator: Griffith, Glenn E.; Bryce, Sandra A.; Omernik, James M.; Comstock, Jeffrey A.; Rogers, Anne C.; Harrison, Bill et al.
System: The Portal to Texas History

A Dad...Teaches, Supports, Plays, Listens, Loves

Bilingual poster depicting a father hugging a child and reading "A Dad...Teaches, Supports, Plays, Listens, Loves," and "Thank you to the unsung heroes of children's lives...loving supportive parents." One side is in English and the other side is in Spanish.
Date: [2002..2015]
Creator: Texas. Department of Health.
System: The Portal to Texas History