223 research outputs found

    Development of a Hand-Held, Flexible Eddy Current Probe for Inspection of Curving Surfaces

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    To enable GE Aircraft Engines to meet stringent engine inspection requirements a new eddy current inspection technology has been developed — the Eddy Current Array Probe (ECAP) [1]. The ECAP is based upon flexible micro-fabricated eddy current sensor elements that are capable of conforming to complex geometries. The technology has been used quite successfully by GE Aircraft Engines to inspect fracture critical aircraft engine components in a manufacturing environment

    Current advances on Talbot–Lau x-ray imaging diagnostics for high energy density experiments (invited)

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    ProducciĂłn CientĂ­ficaTalbot–Lau x-ray interferometry is a refraction-based diagnostic that can map electron density gradients through phase-contrast methods. The Talbot–Lau x-ray deflectometry (TXD) diagnostics have been deployed in several high energy density experiments. To improve diagnostic performance, a monochromatic TXD was implemented on the Multi-Tera Watt (MTW) laser using 8 keV multilayer mirrors (Δξ/Ξ = 4.5%-5.6%). Copper foil and wire targets were irradiated at 1014–1015 W/cm2. Laser pulse length (∌10 to 80 ps) and backlighter target configurations were explored in the context of MoirĂ© fringe contrast and spatial resolution. Foil and wire targets delivered increased contrast <30%. The best spatial resolution (<6 ÎŒm) was measured for foils irradiated 80° from the surface. Further TXD diagnostic capability enhancement was achieved through the development of advanced data postprocessing tools. The Talbot Interferometry Analysis (TIA) code enabled x-ray refraction measurements from the MTW monochromatic TXD. Additionally, phase, attenuation, and dark-field maps of an ablating x-pinch load were retrieved through TXD. The images show a dense wire core of ∌60 ÎŒm diameter surrounded by low-density material of ∌40 ÎŒm thickness with an outer diameter ratio of ∌2.3. Attenuation at 8 keV was measured at ∌20% for the dense core and ∌10% for the low-density material. Instrumental and experimental limitations for monochromatic TXD diagnostics are presented. Enhanced postprocessing capabilities enabled by TIA are demonstrated in the context of high-intensity laser and pulsed power experimental data analysis. Significant advances in TXD diagnostic capabilities are presented. These results inform future diagnostic technique upgrades that will improve the accuracy of plasma characterization through TXD

    Bad news from Fallujah

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    This study uses the thematic analysis developed by the Glasgow University Media Group to explore how the US, UK and German national press covered the US/Coalition assault on the Iraqi city of Fallujah in November 2004. The study relies on quantitative and qualitative full text content analyses to assess 428 news, editorial and commentary items. The article suggests that, while government and military officials of the US/Coalition had argued the military ‘operation’ was necessary to secure Iraq and defeat an ‘insurgency’, organisations and actors from Iraqi society refer to the ‘operation’ as ‘collective punishment’ and a ‘massacre’ that targeted the Iraqi population. The article investigates how the press represented each of these perspectives. The findings suggest that the press overemphasised the US/Coalition perspective despite striking counter evidence. Critical aspects of coverage largely focused on tactical elements of the military dimension of the event. The article concludes that such findings are in accord with hegemonic models of media performance

    Measurement of the Multi-Neutron ΜˉΌ\bar{\nu}_{\mu} Charged Current Differential Cross Section at Low Available Energy on Hydrocarbon

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    Neutron production in antineutrino interactions can lead to bias in energy reconstruction in neutrino oscillation experiments, but these interactions have rarely been studied. MINERvA previously studied neutron production at an average antineutrino energy of ~3 GeV in 2016 and found deficiencies in leading models. In this paper, the MINERvA 6 GeV average antineutrino energy data set is shown to have similar disagreements. A measurement of the cross section for an antineutrino to produce two or more neutrons and have low visible energy is presented as an experiment-independent way to explore neutron production modeling. This cross section disagrees with several leading models' predictions. Neutron modeling techniques from nuclear physics are used to quantify neutron detection uncertainties on this result.Comment: 25 pages, 11 figures; Added ancillary files with cross section values as .csv Matches preprint accepted by publishe

    Simultaneous measurement of muon neutrino ΜΌ\nu_\mu charged-current single π+\pi^+ production in CH, C, H2_2O, Fe, and Pb targets in MINERvA

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    Neutrino-induced charged-current single π+\pi^+ production in the Δ(1232)\Delta(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this work, high statistics differential cross sections are reported for the semi-exclusive reaction ΜΌA→Ό−π++\nu_\mu A \to \mu^- \pi^+ + nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wide-band ΜΌ\nu_\mu beam with \left \approx 6~GeV. Suppression of the cross section at low Q2Q^2 and enhancement of low TπT_\pi are observed in both light and heavy nuclear targets compared to phenomenological models used in current neutrino interaction generators. The cross-section ratios for iron and lead compared to CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.Comment: 6 pages, 6 figures, 117 pages of supplementary material; submitted to Physical Review Letter

    Are Good Intentions Good Enough?: Informed Consent Without Trained Interpreters

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    OBJECTIVE: To examine the informed consent process when trained language interpreters are unavailable. BACKGROUND: Ensuring sufficient patient understanding for informed consent is especially challenging for patients with Limited English Proficiency (LEP). While US law requires provision of competent translation for LEP patients, such services are commonly unavailable. DESIGN AND PARTICIPANTS: Qualitative data was collected in 8 prenatal genetics clinics in Texas, including interviews and observations with 16 clinicians, and 30 Latina patients. Using content analysis techniques, we examined whether the basic criteria for informed consent (voluntariness, discussion of alternatives, adequate information, and competence) were evident for each of these patients, contrasting LEP patients with patients not needing an interpreter. We present case examples of difficulties related to each of these criteria, and compare informed consent scores for consultations requiring interpretation and those which did not. RESULTS: We describe multiple communication problems related to the use of untrained interpreters, or reliance on clinicians’ own limited Spanish. These LEP patients appear to be consistently disadvantaged in each of the criteria we examined, and informed consent scores were notably lower for consultations which occurred across a language barrier. CONCLUSIONS: In the absence of adequate Spanish interpretation, it was uncertain whether these LEP patients were provided the quality and content of information needed to assure that they are genuinely informed. We offer some low-cost practice suggestions that might mitigate these problems, and improve the quality of language interpretation, which is essential to assuring informed choice in health care for LEP patients
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