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Dalitz Plot Analysis of the Decay B0(B0bar) to K^+/- pi^-/+ pi0

Dalitz Plot Analysis of the Decay B0(B0bar) to K^+/- pi^-/+ pi0

Date: September 18, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X. et al.
Description: The authors report a Dalitz-plot analysis of the charmless hadronic decays of neutral B mesons to K{sup {+-}}{pi}{sup {-+}}{pi}{sup 0}. With a sample of (231.8 {+-} 2.6) x 10{sup 6}{Upsilon}(4S) {yields} B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they measure the magnitudes and phases of the intermediate resonant and nonresonant amplitudes for B{sup 0} and {bar B}{sup 0} decays and determine the corresponding CP-averaged branching fractions and charge asymmetries. The inclusive branching fraction and CP-violating charge asymmetry are measured to be {Beta}(B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0}) = (35.7{sub -1.5}{sup +2.6} {+-} 2.2) x 10{sup -6}, and {Alpha}{sub CP} = -0.030{sub -0.051}{sup +0.045} {+-} 0.055 where the first errors are statistical and the second systematic. They observe the decay B{sup 0} {yields} K*{sup 0}(892){pi}{sup 0} with the branching fraction {Beta}(B{sup 0} {yields} K*{sup 0}(892){pi}{sup 0}) = (3.6{sub -0.8}{sup +0.7} {+-} 0.4) x 10{sup -6}. This measurement differs from zero by 5.6 standard deviations (including the systematic uncertainties). The selected sample also contains B{sup 0} {yields} {bar D}{sup 0}{pi}{sup 0} decays where {bar D}{sup 0} {yields} K{sup +}{pi}{sup -}, and they measure {Beta}(B{sup 0} {yields} {bar D}{sup 0}{pi}{sup 0}) = (2.93 ...
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Dalitz-Plot Analysis of the Decays B+/- -> K+/- pi-/+ pi+/-

Dalitz-Plot Analysis of the Decays B+/- -> K+/- pi-/+ pi+/-

Date: October 4, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P. et al.
Description: We report a Dalitz-plot analysis of the charmless hadronic decays of charged B mesons to the state K{sup {+-}} {pi}{sup {-+}}{pi}{sup {+-}}. Using a sample of 226.0 {+-} 2.5 million B{bar B}pairs collected by the BABAR detector, measure the magnitudes and phases of the intermediate resonant and nonresonant amplitudes both charge conjugate decays. We present measurements of the corresponding branching and their charge asymmetries that supersede those of previous BABAR analyses. We find the asymmetries to be consistent with zero.
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Dalitz Plot Study of B0 to K+K-K0s Decays

Dalitz Plot Study of B0 to K+K-K0s Decays

Date: July 27, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P. et al.
Description: We present a study of the dynamics in B{sup 0} {yields} K{sup +}K{sup -}K{sub S}{sup 0} decays with approximately 230 million B{bar B} events collected by the BABAR detector at SLAC. They find that the Dalitz plot distribution is best parameterized with the {phi}K{sub S}{sup 0} mode, an S-wave K{sup +}K{sup -} resonance near 1500 MeV/c{sup 2}, and a large non-resonant contribution. We set limits on resonances not included in the model, and study models for the non-resonant contribution.
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Dallas-Fort Worth clean cities: Award winning coalition

Dallas-Fort Worth clean cities: Award winning coalition

Date: April 27, 2000
Creator: Woodward, S.
Description: Designated a Clean City in 1995, Dallas-Fort Worth now includes 140 coalition members and interested parties who operate more than 5,800 alternative fuel vehicles. Dallas-Fort Worth Clean Cities is administered by the North Central Texas Council of Governments, the metropolitan planning organization for the region, which represents hundreds of municipal and local government agencies.
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Dallas Love Field: The Wright and Shelby Amendments

Dallas Love Field: The Wright and Shelby Amendments

Date: November 9, 2005
Creator: Tatelman, Todd B.
Description: The history of the Wright Amendment dates back to the 1960s when the now defunct Civil Aeronautics Board (CAB) proposed the creation of a single regional airport in the Dallas-Fort Worth (DFW) area. This report discusses legislation affecting the Wright/Shelby restrictions that have been introduced in the 109th Congress.
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Dallas Regional Hearing Transcript, April 19, 1995

Dallas Regional Hearing Transcript, April 19, 1995

Date: unknown
Creator: United States. Defense Base Closure and Realignment Commission.
Description: Dallas Regional Hearing Transcript, April 19, 1995. (B0x 32)
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The Dalles Dam, Columbia River: Spillway Improvement CFD Study

The Dalles Dam, Columbia River: Spillway Improvement CFD Study

Date: June 1, 2006
Creator: Cook, Chris B.; Richmond, Marshall C. & Serkowski, John A.
Description: This report documents development of computational fluid dynamics (CFD) models that were applied to The Dalles spillway for the US Army Corps of Engineers, Portland District. The models have been successfully validated against physical models and prototype data, and are suitable to support biological research and operations management. The CFD models have been proven to provide reliable information in the turbulent high-velocity flow field downstream of the spillway face that is typically difficult to monitor in the prototype. In addition, CFD data provides hydraulic information throughout the solution domain that can be easily extracted from archived simulations for later use if necessary. This project is part of an ongoing program at the Portland District to improve spillway survival conditions for juvenile salmon at The Dalles. Biological data collected at The Dalles spillway have shown that for the original spillway configuration juvenile salmon passage survival is lower than desired. Therefore, the Portland District is seeking to identify operational and/or structural changes that might be implemented to improve fish passage survival. Pacific Northwest National Laboratory (PNNL) went through a sequence of steps to develop a CFD model of The Dalles spillway and tailrace. The first step was to identify a preferred CFD ...
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Dam Removal: Issues, Considerations, and Controversies

Dam Removal: Issues, Considerations, and Controversies

Date: November 20, 2006
Creator: unknown
Description: None
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Dam Removal: Issues, Considerations, and Controversies

Dam Removal: Issues, Considerations, and Controversies

Date: June 19, 2006
Creator: unknown
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Damage Accumulation in MgAl{sub 2}O{sub 4} and Yttria-Stabilized ZrO{sub 2} by Xe-Ion Irradiation

Damage Accumulation in MgAl{sub 2}O{sub 4} and Yttria-Stabilized ZrO{sub 2} by Xe-Ion Irradiation

Date: April 25, 1999
Creator: Afanasyev-Charkin, I.V.; Gritsyna, V.T.; Cooke, D.W.; Bennett, B.L. & Sickafus, K.E.
Description: Magnesium-aluminate spinel (MAS) and yttria-stabilized zirconia (YSZ) are being considered for use as ceramic matrices in proliferation resistant fuels and radioactive storage systems, and may be used either as individual entities or as constituents in multicomponent ceramic systems. It is worthwhile, therefore, to compare radiation damage in these two potentially important materials when subjected to similar irradiation conditions, e.g., ion beam irradiation. To compare radiation damage properties of these two materials, single crystals of spinel and zirconia were irradiated with 340 keV Xe{sup ++} ions at 120 K, and subsequently investigated by Rutherford backscattering and ion channeling (RBS/C), and optical absorption spectroscopy. Results indicate that damage accumulation in both spinel and zirconia follow a three stage process: (1) very slow damage accumulation over a wide range of dose; (2) rapid changes in damage over a range of doses from about 0.25 to 25 displacements per atom (DPA); (3) slower damage accumulation at very high doses and possibly saturation. Optical absorption results indicate that F-centers form in Xe ion-irradiated spinel and that the concentration of these centers saturates at high dose. Absorption bands are also formed in both spinel and zirconia that are due to point defect complexes formed upon irradiation. ...
Contributing Partner: UNT Libraries Government Documents Department
Damage analysis and fundamental studies for fusion reactor materials development for the period March 1, 1991--February 28, 1994. Final report

Damage analysis and fundamental studies for fusion reactor materials development for the period March 1, 1991--February 28, 1994. Final report

Date: January 1, 1995
Creator: Odette, G.R. & Lucas, G.E.
Description: The philosophy of the program at the University of California Santa Barbara has been to develop a fundamental understanding of both the basic damage processes and microstructural evolution that take place in a material during neutron irradiation and the consequent dimensional and mechanical property changes. This fundamental understanding can be used in conjunction with empirical data obtained from a variety of irradiation facilities to develop physically-based models of neutron irradiation effects in structural materials. The models in turn can be used to guide alloy development and to help extrapolate the irradiation data base to the fusion reactor regime. This philosophy is consistent with that of the national and international programs for developing structural materials for fusion reactors. During this period work has encompassed: (1) analysis of the degradation of the mechanical properties of austenitic stainless steels for the purpose of assessing the feasibility of using these steels in ITER; (2) examining helium effects on radiation damage in austenitic and ferritic stainless steels; (3) development and application of electropotential drop techniques to monitor the growth of cracks in steel specimens for a variety of specimen geometries (4) development of advanced methods of measuring fracture properties; (5) combining micromechanical modeling of fracture ...
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Damage and ablation of large band gap dielectrics induced by a 46.9 nm laser beam

Damage and ablation of large band gap dielectrics induced by a 46.9 nm laser beam

Date: March 8, 2006
Creator: Ritucci, A; Tomassetti, G; Reale, A; Arrizza, L; Zuppella, P; Reale, L et al.
Description: We applied a 0.3 mJ, 1.7 ns, 46.9 nm soft X-ray Argon laser to ablate the surface of large band gap dielectrics: CaF{sub 2} and LiF crystals. The ablation versus the fluence of the soft X-ray beam has been studied varying the fluence in the range of 0.05-3 J/cm{sup 2}. An ablation threshold of 0.06 and 0.1 J/cm{sup 2} and an ablation depth of 14 and 20 nm have been found for CaF{sub 2} and LiF, respectively. These results define new ablation conditions for these large band gap dielectrics, which can be of interest for the fine processing of these materials.
Contributing Partner: UNT Libraries Government Documents Department
Damage and fracture in large aperture, fused silica, vacuum spatial filter lenses

Damage and fracture in large aperture, fused silica, vacuum spatial filter lenses

Date: July 7, 1995
Creator: Campbell, J.H.; Edwards, G.J. & Marion, J.E.
Description: Optical damage that results in large scale fracture has been observed in the large, high-fluence, fused-silica, spatial filter lenses on the Nova and Beamlet lasers. In nearly all cases damage occurs on the vacuum side of the lenses and because the vacuum side of the lens is under tensile stress this damage can lead to catastrophic crack growth if the flaw (damage) size exceeds the critical flaw size for SiO{sub 2}. The damaged 52 cm Nova lenses fracture into two and sometimes three large pieces. Although under full vacuum load at the time they fracture, the Nova lenses do not implode. Rather the authors have observed that the pieces lock together and air slowly leaks into the vacuum spatial filter housing through the lens cracks. The Beamlet lenses have a larger aspect ratio and peak tensile stress than Nova. The peak tensile stress at the center of the output surface of the Beamlet lens is 1,490 psi versus 810 psi for Nova. During a recent Beamlet high energy shot, a damage spot on the lens grew to the critical flaw size and the lens imploded. Post shot data indicate the lens probably fractured into 5 to 7 pieces, however, unlike ...
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Damage and repair in skin following exposure to radioactive particles. Progress report for the support period ending 31 July 1975

Damage and repair in skin following exposure to radioactive particles. Progress report for the support period ending 31 July 1975

Date: January 1, 1975
Creator: Forbes, P.D.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Damage Behavior of Aligned and Random Fiber Reinforced Composites for Automotive Applications

Damage Behavior of Aligned and Random Fiber Reinforced Composites for Automotive Applications

Date: September 27, 1999
Creator: Lee, H.K. & Simunovic, S.
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
Damage characterization of a Si{sub 3}N{sub 4}-BN fibrous monolith using NDE techniques.

Damage characterization of a Si{sub 3}N{sub 4}-BN fibrous monolith using NDE techniques.

Date: June 29, 1999
Creator: Deemer, C. M.; Ellingson, W. A.; Finch, J. L.; Staehler, J. M.; Sun, J. G. & Zawada, L. P.
Description: A variety of nondestructive evaluation techniques were utilized to document the damage characteristics of a Si{sub 3}N{sub 4}-BN fibrous monolith. The techniques included X-ray radiography, infrared thermography, ultrasonic C-scanning, and acoustic emission detection. The focus of this paper is the nondestructive evaluation results from a modified single-edge notched tensile specimen inspected before and after testing. Of the techniques performed, the thermography and ultrasonic methods were the most successful at identifying the predominant types of damage incurred in the fibrous monolith material. Polished cross-sections of the specimen revealed that hairline cracks had developed along inter- and intra-laminar BN cell bundle boundaries. Neither type of crack could be identified from the X-ray radiograph. The delaminated zones were matched with results from the thermography and C-scans. The acoustic emissions correlated well with changes in the load-displacement data and provided source locations consistent with the thermal and C-scan images.
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Damage detection algorithms applied to experimental modal data from the I-40 Bridge

Damage detection algorithms applied to experimental modal data from the I-40 Bridge

Date: January 1, 1996
Creator: Farrar, C. & Jauregui, D.
Description: Because the I-40 Bridges over the Rio Grande were to be razed during the summer of 1993, the investigators were able to introduce damage into the structure in order to test various damage identification methods. To support this research effort, New Mexico State University (NMSU) contracted Los Alamos National Laboratory (LANL) to perform experimental modal analyses, and to develop experimentally verified numerical models of the bridge. Previous reports (LA-12767-MS and LA-12979-MS) summarize the results of the experimental modal analyses and the results obtained from numerical modal analyses conducted with finite element models. This report summarizes the application of five damage identification algorithms reported in the technical literature to the previously reported experimental and numerical modal data.
Contributing Partner: UNT Libraries Government Documents Department
Damage Detection and Identification of Finite Element Models Using State-Space Based Signal Processing a Summation of Work Completed at the Lawrence Livermore National Laboratory February 1999 to April 2000

Damage Detection and Identification of Finite Element Models Using State-Space Based Signal Processing a Summation of Work Completed at the Lawrence Livermore National Laboratory February 1999 to April 2000

Date: April 28, 2000
Creator: Burnett, G.C.
Description: Until recently, attempts to update Finite Element Models (FEM) of large structures based upon recording structural motions were mostly ad hoc, requiring a large amount of engineering experience and skill. Studies have been undertaken at LLNL to use state-space based signal processing techniques to locate the existence and type of model mismatches common in FEM. Two different methods (Gauss-Newton gradient search and extended Kalman filter) have been explored, and the progress made in each type of algorithm as well as the results from several simulated and one actual building model will be discussed. The algorithms will be examined in detail, and the computer programs written to implement the algorithms will be documented.
Contributing Partner: UNT Libraries Government Documents Department
Damage detection and model refinement using elemental stiffness perturbations with constrained connectivity

Damage detection and model refinement using elemental stiffness perturbations with constrained connectivity

Date: April 1, 1996
Creator: Doebling, S.W.
Description: A new optimal update method for the correlation of dynamic structural finite element models with modal data is presented. The method computes a minimum-rank solution for the perturbations of the elemental stiffness parameters while constraining the connectivity of the global stiffness matrix. The resulting model contains a more accurate representation of the dynamics of the test structure. The changes between the original model and the updated model can be interpreted as modeling errors or as changes in the structure resulting from damage. The motivation for the method is presented in the context of existing optimal matrix update procedures. The method is demonstrated numerically on a spring-mass system and is also applied to experimental data from the NASA Langley 8-bay truss damage detection experiment. The results demonstrate that the proposed procedure may be useful for updating elemental stiffness parameters in the context of damage detection and model refinement.
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Damage detection for applications undergoing axial (membrane) response

Damage detection for applications undergoing axial (membrane) response

Date: December 1, 1997
Creator: Duffey, T.A.; Farrar, C.R. & Doebling, S.W.
Description: This paper extends and applies recently reported damage identification methods, previously utilized for flexural vibrations only, to axial-type vibrations. The methods are applied to an 8-DOF linear spring-mass system, which models a multi-degree-of-freedom axial or membrane system. The goal of the work is to detect damage (as indicated by reduction in stiffness of one or more of the elements) as well as to locate the damage elements. Two damage detection methods were investigated--the change-in-flexibility method and the damage-index method. Both were found to successfully locate the damaged element(s) for 10% reduction in element stiffness. The change-in-flexibility method indicated damage location even when only a limited number of lower modes were included.
Contributing Partner: UNT Libraries Government Documents Department
Damage detection in aircraft structures using dynamically measured static flexibility matrices

Damage detection in aircraft structures using dynamically measured static flexibility matrices

Date: February 1, 1996
Creator: Robinson, N.A.; Peterson, L.D.; James, G.H. & Doebling, S.W.
Description: Two methods for detecting the location of structural damage in an aircraft fuselage using modal test data are presented. Both methods use the dynamically measured static flexibility matrix, which is assembled from a combination of measured modal vectors, frequencies, and driving point residual flexibilities. As a consequence, neither method requires a mode-to-mode correlation, and both avoid tedious modal discrimination and selection. The first method detects damage as a softening in the point flexibility components, which are the diagonal entries in the flexibility matrix. The second method detects damage from the disassembled elemental stiffnesses as determined using a presumed connectivity. Vibration data from a laser vibrometer is used to measure the modal mechanics of a DC9 aircraft fuselage before and after induced weakening in a longitudinal stringer. Both methods are shown to detect the location of the damage, primarily because the normal stiffness of the reinforced shell of the fuselage is localized to a few square centimeters.
Contributing Partner: UNT Libraries Government Documents Department
DAMAGE DETECTION IN BUILDING JOINTS BY STATISTICAL ANALYSIS.

DAMAGE DETECTION IN BUILDING JOINTS BY STATISTICAL ANALYSIS.

Date: October 1, 2000
Creator: Farrar, C.R. & Allen, D.W.
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
Damage detection in mechanical structures using extreme value statistic.

Damage detection in mechanical structures using extreme value statistic.

Date: January 1, 2002
Creator: Worden, K.; Allen, D. W. (David W.); Sohn, H. (Hoon) & Farrar, C. R. (Charles R.)
Description: The first and most important objective of any damage identification algorithms is to ascertain with confidence if damage is present or not. Many methods have been proposed for damage detection based on ideas of novelty detection founded in pattern recognition and multivariate statistics. The philosophy of novelty detection is simple. Features are first extracted from a baseline system to be monitored, and subsequent data are then compared to see if the new features are outliers, which significantly depart from the rest of population. In damage diagnosis problems, the assumption is that outliers are generated from a damaged condition of the monitored system. This damage classification necessitates the establishment of a decision boundary. Choosing this threshold value is often based on the assumption that the parent distribution of data is Gaussian in nature. While the problem of novelty detection focuses attention on the outlier or extreme values of the data i.e. those points in the tails of the distribution, the threshold selection using the normality assumption weighs the central population of data. Therefore, this normality assumption might impose potentially misleading behavior on damage classification, and is likely to lead the damage diagnosis astray. In this paper, extreme value statistics is integrated ...
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Damage Detection System with Sub-microsecond Resolution

Damage Detection System with Sub-microsecond Resolution

Date: February 11, 2008
Creator: Udd, E & Benterou, J
Description: Fiber optic grating sensors have been used to measure multi-dimensional strain, pressure, temperature, corrosion and moisture. This paper presents a method of using fiber grating sensors to measure the position and velocity of a very fast event associated with a blast wave. A chirped fiber grating of 50 mm length is placed in a highly energetic material. The action of the shock wave is to destroy the fiber grating as it propagates along it. By using a spectral filter such as a chirped fiber grating in combination with high speed detectors the position and velocity of the shock wave may be determined. A layout of a system used to experimentally verify this technique is described and results presented for two different highly energetic materials.
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