Ultrasonic Evaluation of Low Density Powder Compacts

Ultrasonic evaluation of powder compacts provides valuable information about the density of the powder and incipient defects in the compact. Since the specimens would be contaminated if they were inspected with traditional immersion or contact techniques, procedures to dry couple or vacuum bag and immerse the powder samples were implemented. With these methods ultrasonic energy was propagated through the powder compacts and the acoustic velocity and attenuation were measured. The ability to immerse the powder samples not only provides consistent coupling but allows scanning which is a valuable tool to image variations and defects in the compacts

School sport and academic achievement

ABSTRACT BACKGROUND: Physical Education and School Sport (PESS) is an integral part of the school curriculum in Ireland. Historically the Healthy Body, Healthy Mind philosophy has promoted the inclusion of PESS alongside more cognitive school subjects and research suggests that PESS can promote cognitive function and provide educational benefits. However there is little research on how the choice of school sport influences academic achievement. This case study aims to investigate how participation in school sport influences the Leaving Certificate points score in an Irish secondary school. In particular, the study will investigate how the particular sport chosen by students participating in school sport during their Leaving Certificate years influences their Leaving Certificate results. METHODS: The study recorded the Leaving Certificate scores and sporting participation from 402 school children graduating from an all-boys secondary school in the Republic of Ireland during the period 2008-2011. Sports participation was assigned one of four categories: Rugby; Rowing; Soccer; No Sport. RESULTS: Participation in a sport during the Leaving Certificate years conferred a 25.4 point benefit to the final Leaving Certificate score. However, participation in Rowing, the only individual sport available in the study, resulted in significantly higher Leaving Certificate scores than Rugby, Soccer and No Sport (p < .05), conferring an additional 73.4 point benefit over the next highest group, Rugby. CONCLUSION: Promoting participation in school sport and providing access to a range of team and individual sports throughout the secondary school years may be a beneficial way to improve students Leaving Certificate results

Verification and Validation of Computational Models for Ultrasonic Testing

The Pacific Northwest National Laboratory (PNNL) is conducting confirmatory research for the U.S. Nuclear Regulatory Commission (NRC) for the verification and validation of computational models used in ultrasonic testing (UT). This paper discusses some of the findings obtained from simple geometrical reflectors in isotropic, fine-grained, homogeneous materials with conventional ultrasonic transducers. A total of 348 ultrasonic raster scans were acquired using pulse-echo conventional probes with different diameters, beam angles, wave modalities, and frequencies. The raster scans contained reflections from machined notches (flaws) of different sizes and orientations. High frequency pencil beam models, and flaw scattering models employing the Kirchhoff and geometric theory of diffraction approximations, were then used to simulate the corresponding experimental measurements. CIVA, a semi-analytical nondestructive evaluation (NDE) simulation platform developed by the French Commissariat à l’Energie Atomique (CEA), was used to run simulations based on the approximation models. The experimental measurements were compared to their modeled counterparts using quantitative metrics obtained from the C-scans, B-scans and A-scans. To address uncertainties in the input parameters to the computational model, parametric studies and sensitivity analyses were conducted on all the relevant inputs. Sources of discrepancies between the experiment and simulated results are discussed in terms of numerical model errors and uncertainties in the experiments and model input parameters

Teaching with Feminist Judgments: A Global Conversation

This conversational-style essay is an exchange among fourteen professors—representing thirteen universities across five countries—with experience teaching with feminist judgments. Feminist judgments are ‘shadow’ court decisions rewritten from a feminist perspective, using only the precedent in effect and the facts known at the time of the original decision. Scholars in Canada, England, the U.S., Australia, New Zealand, Scotland, Ireland, India, and Mexico have published (or are currently producing) written collections of feminist judgments that demonstrate how feminist perspectives could have changed the legal reasoning or outcome (or both) in important legal cases. This essay begins to explore the vast pedagogical potential of feminist judgments. The contributors to this conversation describe how they use feminist judgments in the classroom; how students have responded to the judgments; how the professors achieve specific learning objectives through teaching with feminist judgments; and how working with feminist judgments—whether studying them, writing them, or both—can help students excavate the multiple social, political, economic, and even personal factors that influence the development of legal rules, structures, and institutions. The primary takeaway of the essay is that feminist judgments are a uniquely enriching pedagogical tool that can broaden the learning experience. Feminist judgments invite future lawyers, and indeed any reader, to re-imagine what the law is, what the law can be, and how to make the law more responsive to the needs of all people

Technical Letter Report - Analysis of Ultrasonic Data on Piping Cracks at Ignalina Nuclear Power Plant Before and After Applying a Mechanical Stress Improvement Process, JCN-N6319, Task 2

Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in piping systems previously analyzed for leak-before-break (LBB). Part of this work involves determining whether inspections alone are sufficient or if inspections plus mitigation techniques are needed. The work described in this report addresses the reliability of ultrasonic phased-array (PA) examinations for inspection of cracks that have been subjected to the mitigation method of mechanical stress improvement process (MSIP). It is believed that stresses imparted during MSIP may make ultrasonic crack responses in piping welds more difficult to detect and accurately characterize. To explore this issue, data were acquired, both before and after applying MSIP, and analyzed from cracked areas in piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. This work was performed under NRC Project JCN-N6319, PWSCC in Leak-Before-Break Systems

Evaluation of Ultrasonic Measurement Variation in the Double-Shell Tank Integrity Project

Washington River Protection Solutions (WRPS) under contract from the U.S. Department of Energy (DOE) is responsible for assessing the condition of the double-shell tanks (DST) on the Hanford nuclear site. WRPS has contracted with AREVA Federal Services LLC (AFS) to perform ultrasonic testing (UT) inspections of the 28 DSTs to assess the condition of the tanks, judge the effects of past corrosion control practices, and satisfy a regulatory requirement to periodically assess the integrity of the tanks. Since measurement inception in 1997, nine waste tanks have been examined twice (at the time of this report) providing UT data that can now be compared over specific areas. During initial reviews of these two comparable data sets, average UT wall-thickness measurement reductions were noted in most of the tanks. This variation could be a result of actual wall thinning occurring on the waste-tanks walls, or some other unexplained anomaly resulting from measurement error due to causes such as the then-current measurement procedures, operator setup, or equipment differences. WRPS contracted with the Pacific Northwest National Laboratory (PNNL) to assist in understanding why this variation exists and where it stems from

Technical Letter Report - Preliminary Assessment of NDE Methods on Inspection of HDPE Butt Fusion Piping Joints for Lack of Fusion

The U.S. Nuclear Regulatory Commission (NRC) has a multi-year program at the Pacific Northwest National Laboratory (PNNL) to provide engineering studies and assessments of issues related to the use of nondestructive evaluation (NDE) methods for the reliable inspection of nuclear power plant components. As part of this program, there is a subtask 2D that was set up to address an assessment of issues related to the NDE of high density polyethylene (HDPE) butt fusion joints. This work is being driven by the nuclear industry wanting to employ HDPE materials in nuclear power plant systems. This being a new material for use in nuclear applications, there are a number of issues related to its use and potential problems that may evolve. The industry is pursuing ASME Code Case N-755 entitled “Use of Polyethylene (PE) Plastic Pipe for Section III, Division 1, Construction and Section XI Repair/Replacement Activities” that contains the requirements for nuclear power plant applications of HDPE. This Code Case requires that inspections be performed after the fusion joint is made by visually examining the bead that is formed and conducting a pressure test of the joint. These tests are only effective in general if gross through-wall flaws exist in the fusion joint. The NRC wants to know whether a volumetric inspection can be conducted on the fusion joint that will reliably detect lack-of-fusion conditions that may be produced during joint fusing. The NRC has requested that the work that PNNL is conducting be provided to assist them in resolving this inspection issue of whether effective volumetric NDE can be conducted to detect lack of fusion (LOF) in the butt HDPE joints. PNNL had 24 HDPE pipe specimens manufactured of 3408 material to contain LOF conditions that could be used to assess the effectiveness of NDE in detecting the LOF. Basic ultrasonic material properties were measured and used to guide the use of phased arrays and time-of-flight diffraction (TOFD) work that was conducted. Millimeter (mm) waves were also used to inspect these assemblies. Fluor and NDE Innovations, Inc. conducted TOFD inspections using their commercially available equipment on all 24 specimens. These NDE inspection results were reviewed and several of the specimens were selected for destructive evaluation using a microtome to slice small blocks of blank and fusion joint material. This interim report provides a status/summary of the work that has been conducted to date. In the areas selected for destructive testing where there were strong acoustic responses, LOF was verified. In areas where there were no NDE responses, no LOF was found. It needs to be noted that only a small amount of material has been destructively characterized at this point and further work is planned to determine if these trends hold up. Some of the material from three of the assemblies was sent off for mechanical testing but the results were not available to be included in this status report. The initial work shows that at least some of the LOF is providing NDE responses that have been verified through destructive testing. Thus, there is promise that a volumetric examination can be conducted on HDPE butt fusion joints. The future work will lead to quantifying what various NDE methods can detect, what they miss, and what they incorrectly characterize as defective

Associations of HDL metrics with coronary artery calcium score and density among women traversing menopause

The cardioprotective association of high-density lipoprotein cholesterol (HDL-C) may vary by menopause stage or estradiol level. We tested whether associations of comprehensive HDL metrics (HDL subclasses, phospholipid and triglyceride content, and HDL cholesterol efflux capacity [HDL-CEC]) with coronary artery calcium (CAC) score and density vary by menopause stage or estradiol level in women transitioning through menopause. Participants (N = 294; mean age [SD]: 51.3 [2.9]) had data on HDL metrics and CAC measures at one or two time points during the menopause transition. Generalized estimating equations were used for analyses. Effect modifications by menopause stage or estradiol level were tested in multivariable models. In adjusted models, menopause stage modified the associations of specific HDL metrics with CAC measures. Higher small HDL particles (HDL-P) concentrations (p-interaction = 0.008) and smaller HDL size (p-interaction = 0.02) were associated with greater odds of CAC presence in late perimenopause than in pre/early perimenopause stage. Women in the highest estradiol tertile, but not the lower tertiles, showed a protective association of small HDL-P with CAC presence (p-interaction = 0.007). Lower large HDL-P concentrations (p-interaction = 0.03) and smaller HDL size (p-interaction = 0.03) were associated with lower CAC density in late perimenopause than in postmenopause stage. Associations of HDL phospholipid and triglyceride content and HDL-CEC with CAC measures did not vary by menopause stage or estradiol level. We concluded that HDL subclasses may impact the likelihood of CAC presence and the stability of coronary plaque differently over the menopause transition. Endogenous estradiol levels may contribute to this observation

Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping