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Alignment validation
The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.
Date:
September 6, 2008
Creator:
ALICE; ATLAS; CMS; LHCb & Golling, Tobias
Object Type:
Article
System:
The UNT Digital Library
Reconfigurable mobile manipulation for accident response
The need for a telerobotic vehicle with hazard sensing and integral manipulation capabilities has been identified for use in transportation accidents where nuclear weapons are involved. The Accident Response Mobile Manipulation System (ARMMS) platform has been developed to provide remote dexterous manipulation and hazard sensing for the Accident Response Group (ARG) at Sandia National Laboratories. The ARMMS' mobility platform is a military HMMWV [High Mobility Multipurpose Wheeled Vehicle] that is teleoperated over RF or Fiber Optic communication channels. ARMMS is equipped with two high strength Schilling Titan II manipulators and a suite of hazardous gas and radiation sensors. Recently, a modular telerobotic control architecture call SMART (Sandia Modular Architecture for Robotic and Teleoperation) has been applied to ARMMS. SMART enables input devices and many system behaviors to be rapidly configured in the field for specific mission needs. This paper summarizes current SMART developments applied to ARMMS.
Date:
June 6, 2000
Creator:
ANDERSON,ROBERT J.; MORSE,WILLIAM D.; SHIREY,DAVID L.; CDEBACA,DANIEL M.; HOFFMAN JR.,JOHN P. & LUCY,WILLIAM E.
Object Type:
Article
System:
The UNT Digital Library
An Archaeological Survey of Proposed Water Pipeline Route Improvements and Deep Well Location for the Cross Country Water Supply Corporation
Archaeological survey results of proposed water pipeline improvements for the Cross County Water Supply Corporation in McLennen and Bosque County, Texas.
Date:
August 6, 2007
Creator:
AR Consultants
Object Type:
Report
System:
The Portal to Texas History
Mass, quark-number, and sqrt sNN dependence of the second andfourth flow harmonics in ultra-relativistic nucleus-nucleuscollisions
We present STAR measurements of the azimuthal anisotropyparameter v_2 for pions, kaons, protons, Lambda, bar Lambda, Xi+bar Xi,and \Omega + bar Omega, along with v_4 for pions, kaons, protons, andLambda + bar Lambda at mid-rapidity for Au+Au collisions at sqrt sNN=62.4and 200 GeV. The v_2(p_T) values for all hadron species at 62.4 GeV aresimilar to those observed in 130 and 200 GeV collisions. For observedkinematic ranges, v_2 values at 62.4, 130, and 200 GeV are as little as10 percent-15 percent larger than those in Pb+Pb collisions at sqrt s NN=17.3 GeV. At intermediate transverse momentum (p_T from 1.5-5 GeV/c),the 62.4 GeV v_2(p_T) and v_4(p_T) values are consistent with thequark-number scaling first observed at 200 GeV. A four-particle cumulantanalysis is used to assess the non-flow contributions to pions andprotons and some indications are found for a smaller non-flowcontribution to protons than pions. Baryon v_2 is larger than anti-baryonv_2 at 62.4 and 200 GeV perhaps indicating either that the initialspatial net-baryon distribution is anisotropic, that the mechanismleading to transport of baryon number from beam- to mid-rapidity enhancesv_2, or that anti-baryon and baryon annihilation is larger in thein-plane direction.
Date:
January 6, 2007
Creator:
Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett,J.; Anderson, B. D. et al.
Object Type:
Article
System:
The UNT Digital Library
Identified particle distributions in pp and Au+Au collisions atsqrt sNN=200 GeV
Transverse mass and rapidity distributions for charged pions, charged kaons, protons and antiprotons are reported for {radical}sNN = 200 GeV pp and Au+Au collisions at RHIC. The transverse mass distributions are rapidity independent within |y| < 0.5, consistent with a boost-invariant system in this rapidity interval. Spectral shapes and relative particle yields are similar in pp and peripheral Au+Au collisions and change smoothly to central Au+Au collisions. No centrality dependence was observed in the kaon and antiproton production rates relative to the pion production rate from medium-central to central collisions. Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and relatively long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.
Date:
October 6, 2003
Creator:
Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type:
Article
System:
The UNT Digital Library
Tank Characterization Report for Single Shell Tank 241-C-104
Interprets information about the tank answering a series of six questions covering areas such as information drivers, tank history, tank comparisons, disposal implications, data quality and quantity, and unique aspects of the tank.
Date:
April 6, 2000
Creator:
Adams, M. R.
Object Type:
Report
System:
The UNT Digital Library
Iran's 2009 Presidential Elections
This report analyzes and discusses Iran's 2009 presidential election, particularly the campaigns of reformist candidate Mir Hussein Musavi and incumbent President Mahmoud Ahmadinejad. Allegations of vote rigging and election fraud have led to protests by supporters of candidate Musavi and have provoked international attention. This report also discusses the Obama Administration's reaction to the election results. This report also discusses briefly the current relationship between the U.S. and Iran, as well as U.S. concerns regarding Iran, such as Iran's efforts at building a nuclear weapons program.
Date:
July 6, 2009
Creator:
Addis, Casey L.
Object Type:
Report
System:
The UNT Digital Library
Results from the CLIC X-Band Structure Test Program at NLCTA
As part of a SLAC-CERN-KEK collaboration on high gradient X-band structure research, several prototype structures for the CLIC linear collider study have been tested using two of the high power (300 MW) X-band rf stations in the NLCTA facility at SLAC. These structures differ in terms of their fabrication (brazed disks and clamped quadrants), gradient profile (amount by which the gradient increases along the structure, which optimizes efficiency and maximizes sustainable gradient) and HOM damping (use of slots or waveguides to rapidly dissipate dipole mode energy). The CLIC goal in the next few years is to demonstrate the feasibility of a CLIC-ready baseline design and to investigate alternatives that could increase efficiency. This paper summarizes the high gradient test results from NLCTA in support of this effort.
Date:
July 6, 2009
Creator:
Adolphsen, Chris; Bowden, Gordon; Dolgashev, Valery; Laurent, Lisa; Tantawi, Sami; Wang, Faya et al.
Object Type:
Article
System:
The UNT Digital Library
Geometric metastability, quivers and holography
We use large N duality to study brane/anti-brane configurations on a class of Calabi-Yau manifolds. With only branes present, the Calabi-Yau manifolds in question give rise to N=2 ADE quiver theories deformed by superpotential terms. We show that the large N duality conjecture of hep-th/0610249 reproduces correctly the known qualitative features of the brane/anti-brane physics. In the supersymmetric case, the gauge theories have Seiberg dualities which are represented as flops in the geometry. Moreover, the holographic dual geometry encodes the whole RG flow of the gauge theory. In the non-supersymmetric case, the large N duality predicts that the brane/anti-brane theories also enjoy such dualities, and allows one to pick out the good description at a given energy scale.
Date:
September 6, 2007
Creator:
Aganagic, Mina; Aganagic, Mina; Beem, Christopher & Freivogel, Ben
Object Type:
Article
System:
The UNT Digital Library
Fluxnet Synthesis Dataset Collaboration Infrastructure
The Fluxnet synthesis dataset originally compiled for the La Thuile workshop contained approximately 600 site years. Since the workshop, several additional site years have been added and the dataset now contains over 920 site years from over 240 sites. A data refresh update is expected to increase those numbers in the next few months. The ancillary data describing the sites continues to evolve as well. There are on the order of 120 site contacts and 60proposals have been approved to use thedata. These proposals involve around 120 researchers. The size and complexity of the dataset and collaboration has led to a new approach to providing access to the data and collaboration support and the support team attended the workshop and worked closely with the attendees and the Fluxnet project office to define the requirements for the support infrastructure. As a result of this effort, a new website (http://www.fluxdata.org) has been created to provide access to the Fluxnet synthesis dataset. This new web site is based on a scientific data server which enables browsing of the data on-line, data download, and version tracking. We leverage database and data analysis tools such as OLAP data cubes and web reports to enable browser …
Date:
February 6, 2008
Creator:
Agarwal, Deborah A.; Humphrey, Marty; van Ingen, Catharine; Beekwilder, Norm; Goode, Monte; Jackson, Keith et al.
Object Type:
Report
System:
The UNT Digital Library
A new security model for collaborative environments
Prevalent authentication and authorization models for distributed systems provide for the protection of computer systems and resources from unauthorized use. The rules and policies that drive the access decisions in such systems are typically configured up front and require trust establishment before the systems can be used. This approach does not work well for computer software that moderates human-to-human interaction. This work proposes a new model for trust establishment and management in computer systems supporting collaborative work. The model supports the dynamic addition of new users to a collaboration with very little initial trust placed into their identity and supports the incremental building of trust relationships through endorsements from established collaborators. It also recognizes the strength of a users authentication when making trust decisions. By mimicking the way humans build trust naturally the model can support a wide variety of usage scenarios. Its particular strength lies in the support for ad-hoc and dynamic collaborations and the ubiquitous access to a Computer Supported Collaboration Workspace (CSCW) system from locations with varying levels of trust and security.
Date:
June 6, 2003
Creator:
Agarwal, Deborah; Lorch, Markus; Thompson, Mary & Perry, Marcia
Object Type:
Article
System:
The UNT Digital Library
LHC Signals from Warped Extra Dimensions
We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the Standard Model (SM) fields propagating in the bulk. We show that the detection of KK gluon is challenging since its production is suppressed by small couplings to the proton's constituents. Moreover, the KK gluon decaysmostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for MKKG<~;; 4 TeV, 100 fb-1 of data at the LHC can provide discovery of the KK gluon. We utilize a sizeable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic"top-jets." We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays ("golden" modes) are suppressed. Our analysis suggests that other frameworks, for example little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely (1) Suppressed production rates for the new particles (such as Z'), due to their"lightfermion-phobic" nature, and (2) Difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and …
Date:
December 6, 2006
Creator:
Agashe, K.; Belyaev, A.; Krupovnickas, T.; Perez, G. & Virzi, J.
Object Type:
Article
System:
The UNT Digital Library
Europe: Rising Economic Nationalism?
None
Date:
July 6, 2006
Creator:
Aheam, Raymond J.
Object Type:
Report
System:
The UNT Digital Library
Europe’s New Trade Agenda
This report summarizes the European Union's new initiative, casts the initiative from a historical perspective, and assesses the implications of this shift for the global trading system and for U.S. interests.
Date:
December 6, 2006
Creator:
Ahearn, Raymond J.
Object Type:
Report
System:
The UNT Digital Library
U.S.-European Union Trade Relations: Issues and Policy Challenges
None
Date:
April 6, 2005
Creator:
Ahearn, Raymond J.
Object Type:
Report
System:
The UNT Digital Library
U.S.-Thailand Free Trade Agreement Negotiations
None
Date:
February 6, 2006
Creator:
Ahearn, Raymond J. & Morrison, Wayne M.
Object Type:
Report
System:
The UNT Digital Library
Thoughts and ''Facts'' From the Ags Polarized Proton Runs During the 1980s.
This workshop's focus is on considering ways for improving the proton beam polarization that the AGS delivers to the RHIC. This talk attempts to review the first decade of AGS polarization--the 1980's; to briefly describe some aspects of the machine situation, the depolarization avoidance strategies employed and the success achieved in AGS from the perspective of one of those involved.
Date:
November 6, 2002
Creator:
Ahrens, L.
Object Type:
Article
System:
The UNT Digital Library
Effect of thin-film coating on wear in EGR-contaminated oil.
Increased use of higher-efficiency compression ignition direct injection (CIDI) diesel engines instead of today's gasoline engines will result in reduced fuel consumption and greenhouse gases emissions. However, NO{sub x} and particulate exhaust emissions from diesel engines must be significantly reduced due to their possible adverse health effects. Exhaust gas recirculation (EGR) is an effective way to reduce NO{sub x} emissions from diesel engines, but the particulates and acidic exhaust products in the recirculated gas will contaminate engine lubricant oil by increasing the soot content and total acid number (TAN). These factors will increase the wear rate in many critical engine components and seriously compromise engine durability. We have investigated the use of commercially available thin and hard coatings (TiN, TiCN, TiAlN, and CrN) to mitigate the negative effects of EGR on wear. In tests with the four-ball machine according to ASTM D4172, we found that all the four coatings deposited on M-50 steel significantly reduced wear in EGR-contaminated oils when compared with uncoated M50 steel balls.
Date:
December 6, 2001
Creator:
Ajayi, O. O.; Aldajah, S. H.; Erdemir, A. & Fenske, G. R.
Object Type:
Article
System:
The UNT Digital Library
Low-friction coatings for air bearings in fuel cell air compressors
In an effort to reduce fuel consumption and emissions, hybrid vehicles incorporating fuel cell systems are being developed by automotive manufacturers, their suppliers, federal agencies (specifically, the US Department of Energy) and national laboratories. The fuel cell system will require an air management subsystem that includes a compressor/expander. Certain components in the compressor will require innovative lubrication technology in order to reduce parasitic energy losses and improve their reliability and durability. One such component is the air bearing for air turbocompressors designed and fabricated by Meruit, Inc. Argonne National Laboratory recently developed a carbon-based coating with low friction and wear attributes; this near-frictionless-carbon (NFC) coating is a potential candidate for use in turbocompressor air bearings. The authors present here an evaluation of the Argonne coating for air compressor thrust bearings. With two parallel 440C stainless steel discs in unidirectional sliding contact, the NFC reduced the frictional force four times and the wear rate by more than two orders of magnitude. Wear mechanism on the uncoated surface involved oxidation and production of iron oxide debris. Wear occurred on the coated surfaces primarily by a polishing mechanism.
Date:
January 6, 2000
Creator:
Ajayi, O. O.; Fenske, G. R.; Erdemir, A.; Woodford, J.; Sitts, J.; Elshot, K. et al.
Object Type:
Article
System:
The UNT Digital Library
Performance of amorphous carbon coating in turbocompressor air bearings.
None
Date:
December 6, 2001
Creator:
Ajayi, O. O.; Woodford, J. B.; Erdemir, A. & Fenske, G. R.
Object Type:
Article
System:
The UNT Digital Library
Peaceful Uses Bona Fides: Criteria for Evaluation and Case Studies
This study applies a set of indicators to assess the peaceful nature of a state’s nuclear program. Evaluation of a country’s nuclear program relative to these indicators can help the international community to take appropriate actions to ensure that the growth of the global nuclear energy industry proceeds peacefully and to minimize nuclear proliferation risks.
Date:
June 6, 2007
Creator:
Ajemian, Chris K.; Hazel, Mike; Kessler, Carol E.; Mathews, Carrie E.; Morris, Fred A.; Seward, Amy M. et al.
Object Type:
Report
System:
The UNT Digital Library
Industrial Applications of Induced Positron Annihilation
This presentation discusses industrial applications of induced positron annihilation.
Date:
October 6, 2004
Creator:
Akers, D.
Object Type:
Presentation
System:
The UNT Digital Library
Variable VHE gamma-ray emission from Markarian 501
The blazar Markarian 501 (Mrk 501) was observed at energies above 100 GeV with the MAGIC telescope from May through July 2005. The high sensitivity of the instrument enabled the determination of the flux and spectrum of the source on a night-by-night basis. Throughout our observational campaign, the flux from Mrk 501 was found to vary by an order of magnitude, and to be correlated with spectral changes. Intra-night flux variability with flux-doubling times down to 2 minutes was also observed. The strength of variability increased with the energy of the {gamma}-ray photons. The energy spectra were found to harden significantly with increasing flux, and a spectral peak clearly showed up during very active states. The position of the spectral peak seems to be correlated with the source luminosity.
Date:
February 6, 2007
Creator:
Albert, Jordi
Object Type:
Article
System:
The UNT Digital Library
Proposal for an EBIS Based RHIC Preinjector
A proposed new heavy ion preinjector for RHIC is described. The progress made at BNL on the development of an Electron Beam Ion Source (EBIS) has increased our confidence that one can build a preinjector meeting RHIC requirements using an EBIS producing intermediate charge state heavy ions. A new RFQ and Linac will be required to accelerate beams from this source to an energy sufficient for injection into the AGS Booster. These are both straightforward devices, very similar to ones already in operation at other laboratories. Injection into the Booster will occur at the same location as the existing heavy ion injection from the Tandem Van de Graaff.
Date:
November 6, 2000
Creator:
Alessi, J. G.; Beebe, E.; Kponou, A.; Pikin, A.; Prelec, K.; Raparia, D. et al.
Object Type:
Article
System:
The UNT Digital Library