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Extending the cereus group genomics to putative food-borne pathogens of different toxicity

Description: The cereus group represents sporulating soil bacteriacontaining pathogenic strains which may cause diarrheic or emetic foodpoisoning outbreaks. Multiple locus sequence typing revealed a presencein natural samples of these bacteria of about thirty clonal complexes.Application of genomic methods to this group was however biased due tothe major interest for representatives closely related to B. anthracis.Albeit the most important food-borne pathogens were not yet defined,existing dataindicate that… more
Date: August 24, 2006
Creator: Lapidus, Alla; Goltsman, Eugene; Auger, Sandrine; Galleron, Nathalie; Segurens, Beatrice; Dossat, Carole et al.
Partner: UNT Libraries Government Documents Department
open access

On the Virial Theorem for Interstellar Medium

Description: An attempt has been made to derive a version of the virial integral that would describe average properties of the interstellar medium (ISM). It is suggested to eliminate the (large) contribution of stellar matter by introducing 'exclusion zones' surrounding stars. Such an approach leads to the appearance of several types of additional surface integrals in the general expression. Their contribution depends on the rate of energy and matter exchange between the stars and ISM. If this exchange is w… more
Date: September 24, 2007
Creator: Ryutov, D.
Partner: UNT Libraries Government Documents Department
open access

System-level modeling for geological storage of CO2

Description: One way to reduce the effects of anthropogenic greenhousegases on climate is to inject carbon dioxide (CO2) from industrialsources into deep geological formations such as brine formations ordepleted oil or gas reservoirs. Research has and is being conducted toimprove understanding of factors affecting particular aspects ofgeological CO2 storage, such as performance, capacity, and health, safetyand environmental (HSE) issues, as well as to lower the cost of CO2capture and related processes. Howe… more
Date: April 24, 2006
Creator: Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan & Bodvarsson, Gudmundur S.
Partner: UNT Libraries Government Documents Department
open access

Sigma: Web Retrieval Interface for Nuclear Reaction Data

Description: The authors present Sigma, a Web-rich application which provides user-friendly access in processing and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The main interface includes browsing using a periodic table and a directory tree, basic and advanced search capabilities, interactive plots of cross sections, angular distributions and spectra, comparisons between evaluated and experimental data, computations between different cross sectio… more
Date: June 24, 2008
Creator: Pritychenko,B. & Sonzogni, A.A.
Partner: UNT Libraries Government Documents Department
open access

Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

Description: Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and anal… more
Date: November 24, 2008
Creator: Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Entropy of near-extremal black holes in AdS5

Description: We construct the microstates of near-extremal black holes in AdS_5 x S5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S5, and we show that they dominate the entropy by directly enumerating them and comparing the results with a partition sum calculation. We display new decoupling limits in which the field theory of the lightest open strings on the D-branes becomes dual to a near-horizo… more
Date: July 24, 2007
Creator: Simon, Joan; Balasubramanian, Vijay; de Boer, Jan; Jejjala, Vishnu & Simon, Joan
Partner: UNT Libraries Government Documents Department
open access

Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

Description: Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile D… more
Date: July 24, 2007
Creator: Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min et al.
Partner: UNT Libraries Government Documents Department
open access

Quantifying the Diffusion of a Fluid through Membranes by RemoteDetection MRI

Description: We present a method to measure self-diffusion acrossmembranes without the need for concentration or pressure gradients.Hyperpolarized xenon in combination with remote detection of NMR allowsthe measurement of membrane permeation, even in the gas phase. Theresulting images allow quantification of the amount of fluid diffusedthrough the membrane, and represent an alternative, potentially moreprecise way of measuring a membrane diffusion coefficient. The use ofremote detection of NMR allows for no… more
Date: October 24, 2006
Creator: Telkki, Ville-Veikko; Hilty, Christian; Garcia, Sandra; Harel,Elad & Pines, Alexander
Partner: UNT Libraries Government Documents Department
open access

Where Water is Oxidized to Dioxygen: Structure of the Photosynthetic Mn4Ca Cluster from X-ray Spectroscopy

Description: Light-driven oxidation of water to dioxygen in plants, algae and cyanobacteria iscatalyzed within photosystem II (PS II) by a Mn4Ca cluster. Although the cluster has been studied by many different methods, the structure and the mechanism have remained elusive. X-ray absorption and emission spectroscopy and EXAFS studies have been particularly useful in probing the electronic and geometric structure, and the mechanism of the water oxidation reaction. Recent progress, reviewed here, includes pola… more
Date: October 24, 2007
Creator: Yano, Junko; Yano, Junko & Yachandra, Vittal K.
Partner: UNT Libraries Government Documents Department
open access

Emittance and Current of Electrons Trapped in a Plasma Wakefield Accelerator

Description: In recent experiments plasma electrons became trapped in a plasma wakefield accelerator (PWFA). The transverse size of these trapped electrons on a downstream diagnostic yields an upper limit measurement of transverse normalized emittance divided by peak current, {var_epsilon}{sub N,x}/I. The lowest upper limit for {var_epsilon}{sub N,x}/I measured in the experiment is 1.3 {center_dot} 10{sup -10} m/A.
Date: September 24, 2008
Creator: Kirby, N.; Blumenfeld, I.; Clayton, C. E.; Decker, F. J.; Hogan, M. J.; Huang, C. et al.
Partner: UNT Libraries Government Documents Department
open access

A High Repetition Rate VUV-Soft X-Ray FEL Concept

Description: We report on design studies for a seeded FEL light source that is responsive to the scientific needs of the future. The FEL process increases radiation flux by several orders of magnitude above existing incoherent sources, and offers the additional enhancements attainable by optical manipulations of the electron beam: control of the temporal duration and bandwidth of the coherent output, reduced gain length in the FEL, utilization of harmonics to attain shorter wavelengths, and precise synchron… more
Date: June 24, 2007
Creator: Corlett, J.; Byrd, J.; Fawley, W. M.; Gullans, M.; Li, D.; Lidia, S. M. et al.
Partner: UNT Libraries Government Documents Department
open access

Does complex absorption behavior leading to conditioning and damage in KDP/DKDP reflect the electronic structure of initiators?

Description: Currently, most of our thinking about the defects responsible for initiating laser damage considers them as featureless absorbers. However, an increasing body of evidence, particularly involving multi-wavelength irradiation, suggests electronic structure of damage initiators is important in determining both initiation and conditioning behaviors in KDP. The effective absorption coefficient of energy under multi-wavelength irradiation cannot be accounted for by a structureless absorber, but is co… more
Date: October 24, 2007
Creator: Feit, M D; DeMange, P P; Negres, R A; Rubenchik, A M & Demos, S G
Partner: UNT Libraries Government Documents Department
open access

Measurement of the tau- to eta pi-pi+pi-nu tau Branching Fraction and a Search for a Second-Class Current in the tau- to eta'(958)pi-nu tau Decay

Description: The {tau}{sup -} {yields} {eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} decay with the {eta} {yields} {gamma}{gamma} mode is studied using 384 fb{sup -1} of data collected by the BABAR detector. The branching fraction is measured to be (1.60 {+-} 0.05 {+-} 0.11) x 10{sup -4}. It is found that {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -} {nu}{sub {tau}} {yields} {eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} is the dominant decay mode with a branching fraction of (1.11 {+-} 0.0… more
Date: March 24, 2008
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Partner: UNT Libraries Government Documents Department
open access

The impact of retail rate structures on the economics of commercial photovoltaic systems in California

Description: This article examines the impact of retail electricity rate design on the economic value of grid-connected photovoltaic (PV) systems, focusing on commercial customers in California. Using 15-min interval building load and PV production data from a sample of 24 actual commercial PV installations, we compare the value of the bill savings across 20 commercial-customer retail electricity rates currently offered in the state. Across all combinations of customers and rates, we find that the annual bi… more
Date: June 24, 2008
Creator: Mills, Andrew D.; Wiser, Ryan; Barbose, Galen & Golove, William
Partner: UNT Libraries Government Documents Department
open access

Can cross sections be accurately known for priori?

Description: Distinct maxima and minima in the neutron total cross section uncertainties were observed in our large scale covariance calculations using a spherical optical potential. In this contribution we investigate the physical origin of this oscillating structure. Specifically, we analyze the case of neutron reactions on {sup 56}Fe, for which total cross section uncertainties are characterized by the presence of five distinct minima at 0.1, 1.1, 5, 25, and 70 MeV. To investigate their origin, we calcul… more
Date: June 24, 2008
Creator: Pigni, M. T.; Dietrich, F. S.; Herman, M. & Oblozinsky, P.
Partner: UNT Libraries Government Documents Department
open access

Depth-resolved soft x-ray photoelectron emission microscopy in nanostructures via standing-wave excited photoemission

Description: We present an extension of conventional laterally resolved soft x-ray photoelectron emission microscopy. A depth resolution along the surface normal down to a few {angstrom} can be achieved by setting up standing x-ray wave fields in a multilayer substrate. The sample is an Ag/Co/Au trilayer, whose first layer has a wedge profile, grown on a Si/MoSi2 multilayer mirror. Tuning the incident x-ray to the mirror Bragg angle we set up standing x-ray wave fields. We demonstrate the resulting depth re… more
Date: November 24, 2008
Creator: Kronast, F.; Ovsyannikov, R.; Kaiser, A.; Wiemann, C.; Yang, S. -H.; Locatelli, A. et al.
Partner: UNT Libraries Government Documents Department
open access

Energy dependence of jet transport parameter and parton saturationin quark-gluon plasma

Description: We study the evolution and saturation of the gluondistribution function in the quark-gluon plasma as probed by apropagating parton and its effect on the computation of jet quenching ortransport parameter $\hat q $. For thermal partons, the saturation scale$Q2_s$ is found to be proportional to the Debye screening mass $\mu_D2$.For hard probes, evolution at small $x=Q2_s/6ET$ leads to jet energydependence of hat q. We study this dependence for both a conformal gaugetheory in weak and strong coupl… more
Date: June 24, 2007
Creator: Casalderrey-Solana, Jorge & Wang, Xin-Nian
Partner: UNT Libraries Government Documents Department
open access

Measurement of electron clouds in large accelerators by microwave dispersion

Description: Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a… more
Date: January 24, 2008
Creator: Desantis, Stefano; De Santis, Stefano; Byrd, John M.; Sonnad, Kiran G.; Pivi, Mauro T.F.; Krasnykh, Anatoly et al.
Partner: UNT Libraries Government Documents Department
open access

Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis

Description: Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and… more
Date: March 24, 2008
Creator: Firestone, Richard B.; Perry, D. L.; English, G. A.; Firestone, R. B.; Leung, K. N.; Garabedian, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Experimental Tests of Cooling: Expectations and Additional Needs

Description: Cooling is a critical aspect for a high-performance Neutrino Factory or a MuonCollider. For this reason, considerable effort is being put toward theexperimental verification of this technique. The international Muon IonizationCooling Experiment, MICE, was approved to operate at Rutherford AppletonLaboratory (RAL) in the UK and beam line commissioning commenced in March, 2008. The MICE collaboration comprises about 130 scientists and engineers from Asia, Europe, and the U.S. In this paper we pre… more
Date: September 24, 2008
Creator: Zisman, Michael S
Partner: UNT Libraries Government Documents Department
open access

Development of a Multi Megawatt Circulator for X Band

Description: Research is in progress on a TeV-scale linear collider that will operate at 5-10 times the energy of present-generation accelerators. This will require development of high power RF sources generating of 50-100 MW per source. Transmission of power at this level requires overmoded waveguide to avoid breakdown. In particular, the TE{sub 01} circular waveguide mode is currently the mode of choice for waveguide transmission at Stanford Linear Accelerator Center (SLAC) in the Multimode Delay Line Dis… more
Date: March 24, 2008
Creator: Neilson, J.; Ives, L. & Tantawi, S. G.
Partner: UNT Libraries Government Documents Department
open access

Testing Large CICC in Short Sample Configuration and Predicting Their Performance in Large Magnets

Description: It is well known that large Nb3Sn Cable-in-Conduit Conductors (CICC) do not always completely utilize current carrying capacity of the strands they are made of. The modern state of theory is not accurate enough to eliminate CICC full scale testing. Measuring properties of large CICC is not a simple task due to variety of parameters that need to be controlled, like temperature, exposure of all the strands to the peak magnetic field, mass flow and particular nonuniform current distribution. The p… more
Date: August 24, 2007
Creator: Martovetsky, N. N.
Partner: UNT Libraries Government Documents Department
open access

The dihadron fragmentation function and its evolution

Description: Dihadron fragmentation functions and their evolution arestudied in the process of e+e- annihilation. Under the collinearfactorization approximation and facilitated by the cut-vertex technique,the two hadron inclusive cross section at leading order (LO) is shown tofactorize into a short distance parton cross section and a long distancedihadron fragmentation function. We provide the definition of such adihadron fragmentation function in terms of parton matrix elements andderive its DGLAP evolutio… more
Date: February 24, 2004
Creator: Majumder, Abhijit & Wang, Xin-Nian
Partner: UNT Libraries Government Documents Department
open access

Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

Description: In this work, we report on the vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuum-ultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of th… more
Date: April 24, 2008
Creator: Kostko, Oleg; Belau, Leonid; Wilson, Kevin R. & Ahmed, Musahid
Partner: UNT Libraries Government Documents Department
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