Resource Type

Country

INTRINSIC RESIDUAL STRESSES IN METAL FILMS SYNTHESIZED BY ENERGETIC PARTICLE DEPOSITION (open access)

INTRINSIC RESIDUAL STRESSES IN METAL FILMS SYNTHESIZED BY ENERGETIC PARTICLE DEPOSITION

None
Date: September 15, 2000
Creator: A. MISRA, M. NASTASI
System: The UNT Digital Library
Some Comments on the La Primavera Geothermal Field, Mexico (open access)

Some Comments on the La Primavera Geothermal Field, Mexico

The La Primavera geothermal field is located about 20 km west of the city of Guadalajara, Jalisco, in the western part of the Mexican Neovolcanic Axis. Initial results of five deep exploration wells (down to 2000 m depth) were very promising; measured downhole temperatures exceed 300{degrees}C. During production, however, downhole temperatures dropped, and the chemistry of the fluids changed. The analysis of geologic, mineralogic, geochemical, and well completion data indicate that colder fluids flow down the wellbore from shallower aqifers cooling the upper zones of the gothermal reservoir. This problem is attributed to inadequate well completions. Doubts have arisen about continuing the exploration of the field because of the somewhat disappointing drilling results. However, a more thorough analysis of all available data indicates that a good geothermal prospect might exist below 3000 m, and that it could be successfully developed with appropriately located and completed wells.
Date: December 15, 1983
Creator: A., Bernardo Dominguez & Lippmann, Marcelo J.
System: The UNT Digital Library
Use of inelastic analysis in cask design (open access)

Use of inelastic analysis in cask design

In this paper, the advantages and disadvantages of inelastic analysis are discussed. Example calculations and designs showing the implications and significance of factors affecting inelastic analysis are given. From the results described in this paper it can be seen that inelastic analysis provides an improved method for the design of casks. It can also be seen that additional code and standards work is needed to give designers guidance in the use of inelastic analysis. Development of these codes and standards is an area where there is a definite need for additional work. The authors hope that this paper will help to define the areas where that need is most acute.
Date: May 15, 2000
Creator: AMMERMAN,DOUGLAS J. & BREIVIK,NICOLE L.
System: The UNT Digital Library
Production of eta mesons in e/sup +/e/sup -/ annihilations at. sqrt. s = 29 GeV (open access)

Production of eta mesons in e/sup +/e/sup -/ annihilations at. sqrt. s = 29 GeV

Data from e/sup +/e/sup -/ annihilations at 29 GeV have been used to measure the production and fragmentation of eta mesons. The signal is observed in the eta ..-->.. ..gamma gamma.. decay channel. The fragmentation function for p/sub eta/ > 1.5 GeV/c agrees well with the shapes predicted by both the Lund and Webber models. However, the mean multiplicity is measured to be < n/sub eta/ > = 0.37 +- 0.08 eta mesons per hadronic annihilation event, which is significantly lower than the values predicted by either model. 6 refs., 2 figs., 1 tab.
Date: June 15, 1987
Creator: Abachi, S.; Akerlof, C.; Baringer, P.; Blockus, D.; Brabson, B.; Brom, J.M. et al.
System: The UNT Digital Library
Study of intermittency in e sup + e sup minus annihilations at 29 GeV (open access)

Study of intermittency in e sup + e sup minus annihilations at 29 GeV

Charged particle multiplicity distributions from e{sup +}e{sup {minus}} annihilations at 29 GeV have been analyzed in selected rapidity and azimuthal angle intervals. The data were taken with the High Resolution Spectrometer at PEP. The factorial moments of the multiplicity distributions increase as the rapidity interval is decreased, the so-called intermittency phenomenon. These direct measurements of the moments agree with values derived from negative binomial fits to our multiplicity distributions in various central rapidity windows. The factorial moments are also given for the distribution in azimuthal angle around the beam direction and for the two-dimensional distribution in rapidity and azimuthal angle around the jet directions.
Date: June 15, 1990
Creator: Abachi, S.; Derrick, M.; Kooijman, P.; Musgrave, B.; Price, L.; Repond, J. et al.
System: The UNT Digital Library
Fermi LAT Observations of the Vela Pulsar (open access)

Fermi LAT Observations of the Vela Pulsar

None
Date: May 15, 2009
Creator: Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC; Atwood, W.B.; /UC, Santa Cruz et al.
System: The UNT Digital Library
Fermi Discovery of Gamma-Ray Emission from NGC 1275 (open access)

Fermi Discovery of Gamma-Ray Emission from NGC 1275

We report the discovery of high-energy (E &gt; 100 MeV) {gamma}-ray emission from NGC 1275, a giant elliptical galaxy lying at the center of the Perseus cluster of galaxies, based on observations made with the Large Area Telescope (LAT) of the Fermi Gamma-ray Space Telescope. The positional center of the {gamma}-ray source is only {approx}3{prime} away from the NGC 1275 nucleus, well within the 95% LAT error circle of {approx}5{prime}. The spatial distribution of {gamma}-ray photons is consistent with a point source. The average flux and power-law photon index measured with the LAT from 2008 August 4 to 2008 December 5 are F{sub {gamma}} = (2.10 {+-} 0.23) x 10{sup -7} ph (&gt;100 MeV) cm{sup -2} s{sup -1} and {Gamma} = 2.17 {+-} 0.05, respectively. The measurements are statistically consistent with constant flux during the four-month LAT observing period. Previous EGRET observations gave an upper limit of F{sub {gamma}} &lt; 3.72 x 10{sup -8} ph (&gt;100 MeV) cm{sup -2} s{sup -1} to the {gamma}-ray flux from NGC 1275. This indicates that the source is variable on timescales of years to decades, and therefore restricts the fraction of emission that can be produced in extended regions of the galaxy cluster. Contemporaneous …
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Ajello, M.; Asano, K.; Baldini, L.; Ballet, J. et al.
System: The UNT Digital Library
Fermi Large Area Telescope Bright Gamma-ray Source List (open access)

Fermi Large Area Telescope Bright Gamma-ray Source List

Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Axelsson, M.; Baldini, L. et al.
System: The UNT Digital Library
Bright AGN Source List from the First Three Months of the Fermi Large Area Telescope All-Sky Survey (open access)

Bright AGN Source List from the First Three Months of the Fermi Large Area Telescope All-Sky Survey

None
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L. et al.
System: The UNT Digital Library
Fermi/LAT Discovery of Gamma-Ray Emission From the Flat-Spectrum Radio Quasar PKS 1454-354 (open access)

Fermi/LAT Discovery of Gamma-Ray Emission From the Flat-Spectrum Radio Quasar PKS 1454-354

None
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J. et al.
System: The UNT Digital Library
The Fermi Gamma Ray Space Telescope discovers the Pulsar in the Young Galactic Supernova-Remnant CTA 1 (open access)

The Fermi Gamma Ray Space Telescope discovers the Pulsar in the Young Galactic Supernova-Remnant CTA 1

Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 ms, a period derivative of 3.614 x 10{sup -13} s s{sup -1}. Its characteristic age of 10{sup 4} years is comparable to that estimated for the SNR. It is conjectured that most unidentified Galactic gamma ray sources associated with star-forming regions and SNRs are such young pulsars.
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, G. et al.
System: The UNT Digital Library
Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope (open access)

Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope

Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of {gamma}-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The {gamma}-ray light curve shows two sharp peaks having phase separation of 0.460 {+-} 0.004, trailing the very narrow radio pulse by 0.200 {+-} 0.003 in phase, very similar to that of other known {gamma}-ray pulsars. The measured {gamma}-ray flux gives an efficiency for the pulsar of {approx}10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, Guido et al.
System: The UNT Digital Library
A limit on {sigma} {center_dot} BR (B{sub c}{sup {+-}} {yields} J/{psi} + {pi}{sup {+-}})/{sigma} {center_dot} BR(B{sub u}{sup {+-}} {yields} J/{psi} + K{sup {+-}}) in {radical}s = 1.8 TeV proton-antiproton collisions (open access)

A limit on {sigma} {center_dot} BR (B{sub c}{sup {+-}} {yields} J/{psi} + {pi}{sup {+-}})/{sigma} {center_dot} BR(B{sub u}{sup {+-}} {yields} J/{psi} + K{sup {+-}}) in {radical}s = 1.8 TeV proton-antiproton collisions

We report on the results of a search for the B{sub c} (b{bar c}) meson in the decay B{sub c}{sup +-} {yields} J/{psi} + {pi}{sup +-}. This search is guided by a control sample of decays of B{sub u} mesons to J/{psi} + K and uses {approx_equal} 75pb{sup -1} of data collected at the Collider Detector Facility (CDF) at Fermilab. The lifetime of the B{sub c} meson is unknown, so the 95% confidence level limit on {sigma} {center_dot} BR(B{sub c} {yields} {psi} + {pi})/{sigma} {center_dot} BR(B{sub u} {yields} {psi} + K) is obtained as a function of the B{sub c} lifetime.
Date: July 15, 1995
Creator: Abe, F.
System: The UNT Digital Library
Crustal Rock Fracture Mechanics for Design and Control of Artificial Subsurface Cracks in Geothermal Energy Extraction Engineering ({Gamma}-Project) (open access)

Crustal Rock Fracture Mechanics for Design and Control of Artificial Subsurface Cracks in Geothermal Energy Extraction Engineering ({Gamma}-Project)

Recently a significant role of artificial and/or natural cracks in the geothermal reservoir has been demonstrated in the literatures (Abe, H., et al., 1983, Nielson, D.L. and Hullen, J.B., 1983), where the cracks behave as fluid paths and/or heat exchanging surfaces. Until now, however, there are several problems such as a design procedure of hydraulic fracturing, and a quantitative estimate of fluid and heat transfer for reservoir design. In order to develop a design methodology of geothermal reservoir cracks, a special distinguished research project, named as ''{Lambda}-Project'', started at Tohoku University (5 years project, 1983-1988). In this project a basic fracture mechanics model of geothermal reservoir cracks is being demonstrated and its validation is being discussed both theoretically and experimentally. This paper descibes an outline of ''{Lambda}-Project''.
Date: December 15, 1983
Creator: Abe, Hiroyuki & Takahashi, Hideaki
System: The UNT Digital Library
Behaviors of Crack-Like Reservoirs by Means of Fracturing at Nigorikawa and Kakkonda Geothermal Fields (open access)

Behaviors of Crack-Like Reservoirs by Means of Fracturing at Nigorikawa and Kakkonda Geothermal Fields

A basic concept of the geothermal reservoir as a set of cracks is first presented. Extensions of subsurface cracks during well stimulation treatments at Nigorikawa(Mori) and closure operations of production well-head valves at Kakkonda are analysed and their behaviors are demonstrated based on results of long-distance AE Measurements.
Date: December 15, 1983
Creator: Abe, Hiroyuki; Takahashi, Hideaki; Nakatsuka, Katsuto; Niitsuma, Hiroaki & Takanohashi, Morihiko
System: The UNT Digital Library
Developing Intelligent Transportation Systems in an Integrated Systems Analysis Environment (open access)

Developing Intelligent Transportation Systems in an Integrated Systems Analysis Environment

We are working on developing an Integrated Systems Analysis Environment (ISAE) for application to analysis and optimization of Intelligent Transportation Systems (ITS). ISAE is based on the concept of Co-simulation, which allows the modeling of complex systems with extreme flexibility. Co-simulation allows the development of virtual ITS systems that can be analyzed and optimized as an overall integrated system. The virtual ITS system is defined by selecting different components from a component library. System component models can be written in multiple programming languages running on different computer platforms. At the same time, ISAE provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all system components. Co-simulation has been recently demonstrated using an example of an automotive system. The demonstration was successfully performed. The paper describes plans on how to implement ISAE and Co-simulation to ITS, and the great advantages that this implementation would represent.
Date: January 15, 2002
Creator: Aceves, S. M. & Paddack, E. E.
System: The UNT Digital Library
A hybrid vehicle evaluation code and its application to vehicle design (open access)

A hybrid vehicle evaluation code and its application to vehicle design

This report describes a hybrid vehicle simulation model, which can be applied to many of the vehicles currently being considered for low pollution and high fuel economy. The code operates interactively, with all the vehicle information stored in data files. The code calculates fuel economy for three driving schedules, time for 0-96 km/h at maximum acceleration, hill climbing performance, power train dimensions, and pollution generation rates. This report also documents the application of the code to a hybrid vehicle that operates with a hydrogen internal combustion engine. The simulation model is used for parametric studies of the vehicle. The results show the fuel economy of the vehicle as a function of vehicle mass, aerodynamic drag, engine-generator efficiency, flywheel efficiency, and flywheel energy and power capacities.
Date: July 15, 1994
Creator: Aceves, S. M. & Smith, J. R.
System: The UNT Digital Library
A hybrid vehicle evaluation code and its application to vehicle design. Revision 1 (open access)

A hybrid vehicle evaluation code and its application to vehicle design. Revision 1

This paper describes a hybrid vehicle simulation model which can be applied to many of the vehicles currently being considered for low pollution and high fuel economy. The code operates in batch mode with all the vehicle information stored in data files. The code calculates fuel economy for three driving schedules, time for 0--96 km/h at maximum acceleration, hill climbing performance, power train dimensions, and pollution generation rates. This paper also documents the application of the code to a hybrid vehicle that utilizes a hydrogen internal combustion engine. The simulation model is used for parametric studies of the vehicle. The results show the fuel economy of the vehicle as a function of vehicle mass, aerodynamic drag, engine efficiency, accessory load, and flywheel efficiency. The code also calculates the minimum flywheel energy and power to obtain a desired performance. The hydrogen hybrid vehicle analyzed in the paper has a predicted range of 480 km (300 miles), with a gasoline equivalent fuel efficiency of 34.2 km/liter (80.9 mpg).
Date: September 15, 1994
Creator: Aceves, S. M. & Smith, J. R.
System: The UNT Digital Library
Fermi-LAT Search for Pulsar Wind Nebulae Around Gamma-Ray Pulsars (open access)

Fermi-LAT Search for Pulsar Wind Nebulae Around Gamma-Ray Pulsars

None
Date: June 15, 2012
Creator: Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D. et al.
System: The UNT Digital Library
Centrality and pseudorapidity dependence of charged hadron production at intermediate p{sub T} in Au+Au collisions at {radical}s{sub NN} = 130 GeV (open access)

Centrality and pseudorapidity dependence of charged hadron production at intermediate p{sub T} in Au+Au collisions at {radical}s{sub NN} = 130 GeV

We present STAR measurements of charged hadron production as a function of centrality in Au + Au collisions at {radical}s{sub NN} = 130 GeV. The measurements cover a phase space region of 0.2 &lt; p{sub T} &lt; 6.0 GeV/c in transverse momentum and -1 &lt; {eta} &lt; 1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5 &lt; |{eta}| &lt; 1 are reported and compared to our previously published results for |{eta}| &lt; 0.5. No significant difference is seen for inclusive p{sub T} distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d{eta} distributions and truncated mean p{sub T} in a region of p{sub T} &gt; p{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured p{sub T} region. The relative importance of hard scattering process is investigated through binary scaling fraction of particle production.
Date: April 15, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
System: The UNT Digital Library
Centrality and pseudorapidity dependence of charged hadron production at intermediate p{sub t} in Au+Au collisions at {radical}s{sub NN} = 130 GeV (open access)

Centrality and pseudorapidity dependence of charged hadron production at intermediate p{sub t} in Au+Au collisions at {radical}s{sub NN} = 130 GeV

We present STAR measurements of charged hadron production as a function of centrality in Au + Au collisions at {radical}s{sub NN} = 130 GeV. The measurements cover a phase space region of 0.2 &lt; p{sub T} &lt; 6.0 GeV/c in transverse momentum and 11 &lt; {eta} &lt; 1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5 &lt; |{eta}| &lt; 1 are reported and compared to our previously published results for |{eta}| &lt; 0.5. No significant difference is seen for inclusive p{sub T} distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d{eta} distributions and truncated mean p{sub T} in a region of p{sub T} &gt; P{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured pT region. The relative importance of hard scattering process is investigated through binary scaling fraction of particle production.
Date: April 15, 2004
Creator: Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
System: The UNT Digital Library
Magnetic correlations in doped transition metal oxides (open access)

Magnetic correlations in doped transition metal oxides

The authors review recent reactor- and spallation-source-based neutron scattering experiments on the magnetic fluctuations and order in a variety of doped transition metal oxides. In particular, data are shown for the NiO chain compound, Y{sub 2{minus}x}Ca{sub x}BaNiO{sub 5}, the two-dimensional cuprate superconductors La{sub 2{minus}x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3} O{sub 6+x}, and the classical three-dimensional ``Mott-Hubbard`` system V{sub 2{minus}y}O{sub 3}.
Date: February 15, 1995
Creator: Aeppli, G.; Bao, W. & Broholm, C.
System: The UNT Digital Library
Deletion of ultraconserved elements yields viable mice (open access)

Deletion of ultraconserved elements yields viable mice

Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.
Date: July 15, 2007
Creator: Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A. et al.
System: The UNT Digital Library
The Adiabatic Matching Section Solution for the Source Injector (open access)

The Adiabatic Matching Section Solution for the Source Injector

Typical designs for a Heavy Ion Fusion Power Plant require the source injector to deliver 100 beams, packed into an array with a spacing of 7 cm. When designing source injectors using a single large aperture source for each beam, the emitter surfaces are packed into an array with a spacing of 30 cm. Thus, the matching section of the source injector must not only prepare the beam for transport in a FODO lattice, but also funnel the beams together. This can be accomplished by an ESQ matching section in which each beam travels on average at a slight angle to the axis of the quadrupoles and uses the focusing effect of the FODO lattice to maintain the angle. At the end of the matching section, doublet steering is used to bring the beams parallel to each other for injection into the main accelerator. A specific solution of this type for an 84-beam source injector is presented. PACS: 41.75.Ak,41.85.Ar, 41.85.Ja
Date: September 15, 2000
Creator: Ahle, L.; Grote, D. P.; Halaxa, E.; Henestroza, E.; Kwan, J. W. & Mac Laren, S. A.
System: The UNT Digital Library