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The Wynnewood Gazette (Wynnewood, Okla.), Vol. 107, No. 40, Ed. 1 Thursday, December 31, 2009
Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date:
December 31, 2009
Creator:
unknown
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Wyoming DOE EPSCoR
All of the research and human resource development projects were systemic in nature with real potential for becoming self sustaining. They concentrated on building permanent structure, such as faculty expertise, research equipment, the SEM Minority Center, and the School of Environment and Natural Resources. It was the intent of the DOE/EPSCoR project to permanently change the way Wyoming does business in energy-related research, human development for science and engineering careers, and in relationships between Wyoming industry, State Government and UW. While there is still much to be done, the DOE/EPSCoR implementation award has been successful in accomplishing that change and enhancing UW's competitiveness associated with coal utilization, electrical energy efficiency, and environmental remediation.
Date:
January 15, 2004
Creator:
Gern, W.A.
Object Type:
Report
System:
The UNT Digital Library
Wyoming Emergency Management and Homeland Security Statutory Authorities Summarized
This report is one of a series that profiles the emergency management and homeland security statutory authorities of the 50 states, the District of Columbia, the Commonwealth of the Northern Mariana Islands, the Commonwealth of Puerto Rico, and three territories (American Samoa, Guam, and the U.S. Virgin Islands). Each profile identifies the more significant elements of state statutes, generally as codified. This report focuses on the state of Wyoming.
Date:
September 3, 2004
Creator:
Bea, Keith; Runyon, L. Cheryl & Warnock, Kae M.
Object Type:
Report
System:
The UNT Digital Library
[Wyverns as Acroteria: Guardians of the Old Red Museum]
Four magnificent terra cotta creatures, shaped like wyverns with two legs, wings, and spiny backs, grace the rooftop of the Old Red Museum. These mythical beings, known as acroteria, stand as guardians, overlooking the historic building and its rich history. While two of these awe-inspiring figures are original, the other two were meticulously reconstructed during the restoration process in the 2000s, preserving their significance in the museum's captivating architecture.
Date:
March 2008
Creator:
Mallory, Randy
Object Type:
Photograph
System:
The UNT Digital Library
X-38 Crew Return Vehicle
Photograph of the crew return vehicle located in Hanger X at Johnson Space Center, NASA in Houston, Texas. The spacecraft is propped up on blocks and there is a sign at one side that says "X-38 Crew Return Vehicle." The walls of the hangar are visible in the background, covered in foil insulation.
Date:
May 3, 2005
Creator:
Belden, Dreanna L.
Object Type:
Photograph
System:
The Portal to Texas History
X-38 Crew Return Vehicle at Hanger X
Photograph of the front portion of the X-38 crew return vehicle housed in Hanger X at Johnson Space Center in Houston, Texas. There is a picture of the U.S. flag and "United States" written on the side of the vehicle near the nose. It is surrounded by a short glass fence and part of the hangar is visible in the background.
Date:
May 3, 2005
Creator:
Belden, Dreanna L.
Object Type:
Photograph
System:
The Portal to Texas History
X-0557 modified Steven tests : series I and II /.
Low-velocity mechanical impact leading to unintentional reaction is of concern in accident scenarios involving the handling, transport, and storage of high explosives (HE). These have been investigated using different experimental techniques, from small- to large-scale, including, but not limited to the drop weight impact, Taylor anvil impact, Susan,1 and more recently, the Steven and Modified Steven tests.2-8 Ideally, the data will be used to further advance 3-D finite element analysis predictive capability with improved bulk constitutive HE models for the assessment of HE response to mechanical insult. Our overall objectives for these experiments were to (1) evaluate the HE reaction threshold behavior for two different lots of X-0557, and (2) characterize the degree of reaction violence relative to a detonation. This report summarizes our single impact test results on the two different lots of X-0557 in Modified Steven targets.
Date:
January 1, 2002
Creator:
Straight, James W.; Osborn, Michael A.; Coulter, William L.; Mang, Joseph T.; Anderson, Mark C. & Idar, Deanne J.
Object Type:
Article
System:
The UNT Digital Library
The X(3872) at the Tevatron
The author reports results on the X(3872) from the Tevatron. Mass and other properties have been studied, with a focus on new results on the dipion mass spectrum in X {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays. Dipions favor interpreting the decay as J/{psi}{rho}, implying even C-parity for the X. Modeling uncertainties do not allow distinguishing between S- and P-wave decays of the J/{psi}-{rho} mode. Effects of {rho}-{omega} interference in X decay are also introduced.
Date:
November 1, 2005
Creator:
Bauer, G.
Object Type:
Article
System:
The UNT Digital Library
The X(3872) boson: Molecule or charmonium
It has been argued that the mystery boson X(3872) is a molecular state consisting of primarily D{sup 0}{bar D}*{sup 0} + {bar D}{sup 0}D*{sup 0}. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). They examine several aspects of these alternatives by semi-quantitative methods since quantitatively accurate results are often hard to reach on them. they point out that some of the observed properties of X(3872), in particular, the binding and the production rates are incompatible with the molecule interpretation. Despite puzzles and obstacles, X(3872) may fit more likely to the excited {sup 3}P{sub 1} charmonium than to the molecule after the mixing of c{bar c} with D{bar D}* + {bar D}D* is taken into account.
Date:
August 1, 2005
Creator:
Suzuki, Mahiko
Object Type:
Article
System:
The UNT Digital Library
X-BAND KLYSTRON DEVELOPMENT AT SLAC
The development of X-band klystrons at SLAC originated with the idea of building an X-band Linear Collider in the late 1980's. Since then much effort has been expended in developing a reliable X-band Power source capable of delivering >50 MW RF power in pulse widths >1.5 {micro}s. I will report on some of the technical issues and design strategies which have led to the current SLAC klystron designs.
Date:
August 3, 2009
Creator:
Vlieks, Arnold E.
Object Type:
Article
System:
The UNT Digital Library
X-Band Traveling Wave Rf Deflector Structures
Design studies on the X-Band transverse RF deflectors operating at HEM{sub ll} mode have been made for two different applications. One is for beam measurement of time-sliced emittance and slice energy spread for the upgraded LCLS project, its optimization in RF efficiency and system design are carefully considered. Another is to design an ultra-fast RF kicker in order to pick up single bunches from the bunch-train of the B-factory storage ring. The challenges are to obtain very short structure filling time with high RF group velocity and good RF efficiency with reasonable transverse shunt impedance. Its RF system will be discussed.
Date:
December 18, 2008
Creator:
Wang, J. W. & Tantawi, S.
Object Type:
Article
System:
The UNT Digital Library
X-O557 MODIFIED STEVEN TESTS: SERIES I AND II
None
Date:
January 1, 2002
Creator:
IDAR, D. J.; STRAIGHT, J. W. & AL, ET
Object Type:
Article
System:
The UNT Digital Library
X-Ray Absorption and Soft X-Ray Fluorescence Analysis of Kdp Optics
Potassium Dihydrogen Phosphate (KDP) is a non-linear optical material used for laser frequency conversion and optical switches. Unfortunately, when KDP crystals are coated with a porous silica anti-reflection coating [1] and then exposed to ambient humidity, they develop dissolution pits [2,3]. Previous investigations [2] have shown that thermal annealing renders KDP optics less susceptible to pitting suggesting that a modification of surface chemistry has occurred. X-ray absorption and fluorescence were used to characterize changes in the composition and structure of KDP optics as a function of process parameters. KDP native crystals were also analyzed to provide a standard basis for interpretation. Surface sensitive total electron yield and bulk sensitive fluorescence yield from the K 2p, P 2p (L{sub 2,3}-edge) and O 1s (K-edge) absorption edges were measured at each process step. Soft X-ray fluorescence was also used to observe changes associated with spectral differences noted in the absorption measurements. Results indicate that annealing at 160 C dehydrates the surface of KDP resulting in a metaphosphate surface composition with K:P:O = 1:1:3.
Date:
August 9, 2000
Creator:
Nelson, A. J.; van Buuren, T.; Miller, E.; Land, T. A.; Bostedt, C.; Franco, N. et al.
Object Type:
Article
System:
The UNT Digital Library
An X-ray Absorption Edge Detector for High-Resolution Measurement of Undulator Effective K-Parameter
The spectrum of angle-integrated undulator radiation displays a sharp edge at every harmonic photon energy. A technique utilizing this feature to measure minute changes in K-parameters of an undulator in a free-electron laser has been proposed. To date, this technique requires the use of crystal monochromators as bandpass filters whose energy centroid depends on the incident angle of the x-ray beam. In this work we propose to use the absorption edge of an appropriate element as an energy-selective detector whose response is truly independent of the angle of the x-ray beam, and hence independent of electron beam direction and emittance. We will discuss the basic design concept of the detection system and illustrate its projected performance with computer simulations.
Date:
March 7, 2007
Creator:
Yang, B.; /Argonne & Galayda, J.N.
Object Type:
Article
System:
The UNT Digital Library
X-ray Absorption Spectroscopy
This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.
Date:
July 9, 2009
Creator:
Yano, Junko & Yachandra, Vittal K.
Object Type:
Article
System:
The UNT Digital Library
X-ray Absorption Spectroscopy and Density Functional Theory Studies of [(H3buea)FeIII-X]n1 (X= S2-, O2-,OH-): Comparison of Bonding and Hydrogen Bonding in Oxo and Sulfido Complexes
Iron L-edge, iron K-edge, and sulfur K-edge X-ray absorption spectroscopy was performed on a series of compounds [Fe{sup III}H{sub 3}buea(X)]{sup n-} (X = S{sup 2-}, O{sup 2-}, OH{sup -}). The experimentally determined electronic structures were used to correlate to density functional theory calculations. Calculations supported by the data were then used to compare the metal-ligand bonding and to evaluate the effects of H-bonding in Fe{sup III}-O vs Fe{sup III-}S complexes. It was found that the Fe{sup III-}O bond, while less covalent, is stronger than the FeIII-S bond. This dominantly reflects the larger ionic contribution to the Fe{sup III-}O bond. The H-bonding energy (for three H-bonds) was estimated to be -25 kcal/mol for the oxo as compared to -12 kcal/mol for the sulfide ligand. This difference is attributed to the larger charge density on the oxo ligand resulting from the lower covalency of the Fe-O bond. These results were extended to consider an Fe{sup IV-}O complex with the same ligand environment. It was found that hydrogen bonding to Fe{sup IV-}O is less energetically favorable than that to Fe{sup III-}O, which reflects the highly covalent nature of the Fe{sup IV-}O bond.
Date:
September 27, 2006
Creator:
Dey, Abhishek; Hocking, Rosalie K.; /Stanford U., Chem. Dept.; Larsen, Peter; Borovik, Andrew S.; U., /Kansas et al.
Object Type:
Article
System:
The UNT Digital Library
X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator
Young plants of Stackhousia tryonii Bailey were exposed to 34 mM Ni kg-1 in the form of NiSO4- 6H2O solution and grown under controlled glasshouse conditions for a period of 20 days. Fresh leaf, stem and root samples were analysed in vivo by micro x-ray absorption spectroscopy (XAS) at the Ni-K edge.Both x-ray absorption near edge structure and extended x-ray absorption fine structure spectra were analysed, and theresulting spectra were compared with spectra obtained from nine biologically important Ni-containing model compounds. The results revealed that themajority of leaf, stem and root Ni in the hyperaccumulator was chelated by citrate.Our results also suggest that in leavesNi is complexed by phosphate and histidine, and in stems and roots, phytate and histidine. The XAS results provide an important physiological insightinto transport, detoxification and storage of Ni in S. tryonii plants.
Date:
October 8, 2007
Creator:
Ionescu, Mihail; Bhatia, Naveen P.; Cohen , David D.; Siegele, R.; Marcus, Matthew A.; Fakra, Sirine C. et al.
Object Type:
Article
System:
The UNT Digital Library
X-ray Absorption Spectroscopy Characterization of Zn Underpotential Deposition on Au(111) from Phosphate Supporting Electrolyte
Zn K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the structure of Zn monolayers prepared on Au(111) electrodes via underpotential deposition (UPD) from phosphate supporting electrolyte. Theoretical modeling of the XAS data indicates that the Zn adatoms adopt a commensurate ({radical}3x{radical}3)R30{sup o} ({mu}{sub sc} = 0.33) adlayer structure and reside within the 3-fold hollow sites of the Au(111) surface. Meanwhile, phosphate counter-ions co-adsorb on the UPD adlayer and bridge between the Zn adatoms in a ({radical}3x{radical}3)R30{sup o} ({mu}{sub sc} = 0.33) configuration, with each phosphorous atom residing above a vacant 3-fold hollow site of the Au(111). Significantly, this surface structure is invariant between the electrochemical potential for UPD adlayer formation and the onset of bulk Zn electrodeposition. Analysis of the Zn K-edge absorption onset also presents the possibility that the Zn adatoms do not fully discharge during the process of UPD, which had been proposed in prior voltammetric studies of the phosphate/Zn(UPD)/Au(111) system.
Date:
December 11, 2009
Creator:
Lee, J. R.; O'Malley, R. L.; O'Connell, T. J.; Vollmer, A. & Rayment, T.
Object Type:
Article
System:
The UNT Digital Library
X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films
None
Date:
June 5, 2002
Creator:
Richardson, Thomas; Farangis, Baker; Slack, J.L.; Nachimuthu, P.; Perera, R.; Tamura, N. et al.
Object Type:
Article
System:
The UNT Digital Library
X-Ray Absorption Spectroscopy of Yb3+-Doped Optical Fibers
Optical fibers doped with Ytterbium-3+ have become increasingly common in fiber lasers and amplifiers. Yb-doped fibers provide the capability to produce high power and short pulses at specific wavelengths, resulting in highly effective gain media. However, little is known about the local structure, distribution, and chemical coordination of Yb3+ in the fibers. This information is necessary to improve the manufacturing process and optical qualities of the fibers. Five fibers doped with Yb3+ were studied using Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy and X-ray Absorption Near Edge Spectroscopy (XANES), in addition to Yb3+ mapping. The Yb3+ distribution in each fiber core was mapped with 2D and 1D intensity scans, which measured X-ray fluorescence over the scan areas. Two of the five fibers examined showed highly irregular Yb3+ distributions in the core center. In four of the five fibers Yb3+ was detected outside of the given fiber core dimensions, suggesting possible Yb3+ diffusion from the core, manufacturing error, or both. X-ray absorption spectroscopy (XAS) analysis has so far proven inconclusive, but did show that the fibers had differing EXAFS spectra. The Yb3+ distribution mapping proved highly useful, but additional modeling and examination of fiber preforms must be conducted to improve XAS …
Date:
January 1, 2008
Creator:
Citron, Robert & Kropf, A. Jeremy
Object Type:
Article
System:
The UNT Digital Library
X-ray absorption studies of the local structure and f-level occupancy in CeIr(1-x)Rh(x)In(5)
The CeIr{sub 1-x}Rh{sub x}In{sub 5} series exhibits a range of interesting phenomena, including heavy-fermion superconductivity, non-Fermi liquid behavior, and concomitant antiferromagnetism (AF) and superconductivity (SC). In the low-Rh concentration range (0.1 {ge} x {ge} 0.5), specific heat measurements show a broad anomaly, suggestive of gross phase separation. We have performed x-ray absorption experiments at the Ce L{sub III}, Ir L{sub III}, and Rh K-edges as a function of Rh concentration and temperature. X-ray absorption near-edge structure (XANES) measurements indicate that cerium is close to trivalent in this system, with no measurable change with temperature from 20-300 K, consistent with a heavy-fermion material. Extended x-ray absorption fine structure (EXAFS) measurements as a function of temperature from all measured edges indicate the local crystal structure of all samples is well ordered, with no gross phase separation observed, even for samples with x = 0.125 and x = 0.25. These results therefore suggest that the anomalous specific heat behavior in the 0.1 {ge} x {ge} 0.5 range have some other explanation, and some possibilities are discussed.
Date:
April 15, 2004
Creator:
Daniel, M.; Han, S. W.; Booth, C. H.; Cornelius, A. L.; Pagliuso, P. G.; Sarrao, J. L. et al.
Object Type:
Article
System:
The UNT Digital Library
X-Ray Absorption Studies of Vanadium-Containing Metal Oxide Nanocrystals
Metal oxide nanocrystals offer significant potential for use as catalysts or catalyst supports due to their high surface areas and unique chemical properties that result from the high number of exposed corners and edges. However, little is known about the catalytic activity of these materials, especially as oxidation catalysts. This research focused on the preparation, characterization and use of vanadium-containing nanocrystals as selective oxidation catalysts. Three vanadium-containing nanocrystals were prepared using a modified sol-gel procedure: V/MgO, V/SiO2, and vanadium phosphate (VPO). These represent active oxidation catalysts for a number of industrially relevant reactions. The catalysts were characterized by x-ray diffraction and Raman, UV-VIS, infrared and x-ray absorption spectroscopies with the goal of determining the primary structural and chemical differences between nanocrystals and microcrystals. The catalytic activity of these catalysts was also studied in oxidative dehydrogenation of butane and methanol oxidation to formaldehyde. V/MgO nanocrystals were investigated for activity in oxidative dehydrogenation of butane and compared to conventional V/MgO catalysts. Characterization of V/MgO catalysts using Raman spectroscopy and x-ray absorption spectroscopy showed that both types of catalysts contained magnesium orthovanadate at vanadium loadings below 15 weight%, but above that loading, magnesium pyrovanadate may have been present. In general, MgO nanocrystals had …
Date:
January 9, 2006
Creator:
Hohn, Keith, L.
Object Type:
Report
System:
The UNT Digital Library
X-ray absorption study of the electronic structure of Mn-doped amorphous Si
The electronic structure of Mn in amorphous Si (a-Mn{sub x}Si{sub 1?x}) is studied by X-ray absorption spectroscopy at the Mn L{sub 3,2} edges for x = 0.005-0.18. Except the x = 0.005 sample, which shows a slight signature of Mn{sup 2+} atomic multiplets associated with a local Mn moment, all samples have broad and featureless L{sub 3,2} absorption peaks, corresponding to an itinerant state for all 3d electrons. The broad X-ray absorption spectra exclude the possibility of a localized 3d moment and explain the unexpectedly quenched Mn moment in this magnetically-doped amorphous semiconductor. Such a fully delocalized d state of Mn dopant in Si has not been previously suggested.
Date:
March 8, 2008
Creator:
Arenholz, Elke; Zeng, Li; Huegel, A.; Helgren, E.; Hellman, F.; Piamonteze, C. et al.
Object Type:
Article
System:
The UNT Digital Library
X-Ray Active Matrix Pixel Sensors Basedon J-FET Technology Developed for the Linac Coherent Light Source.
An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.
Date:
October 29, 2007
Creator:
Carini, G. A.; Chen, W.; Li, Z.; Rehak, P. & Siddons, D. P.
Object Type:
Article
System:
The UNT Digital Library