The thermographic nondestructive evaluation of iron aluminide green sheet

The recent development of manufacturing techniques for the fabrication of thin iron aluminide sheet requires advanced quantitative methods for on-line inspection. An understanding of the mechanisms responsible for flaws and the development of appropriate flaw detection methods are key elements in an effective quality management system. The first step in the fabrication of thin FeAl alloy sheet is the formation of a green sheet by cold rolling FeAl powder mixed with organic binding agents. The green sheet composite has a bulk density, which is typically less than about 3.6 g/cc. The finished sheet, with a density of about 6.1 g/cc, is obtained using a series of process steps involving binder elimination, densification, sintering, and annealing. Non-uniformities within the green sheet are the major contributor to material failure in subsequent sheet processing and the production of non-conforming finished sheet. The production environment and physical characteristics of the composite provide for unique challenges in developing a rapid nondestructive inspection capability. The method must be non-contact due to the fragile nature of the composite. Limited access to the material also demands a one-sided inspection technique. An active thermographic method providing for 100% on-line inspection within an industrial, process has been developed. This approach is cost competitive with alternative technologies, such as x-ray imaging systems, and provides the required sensitivity to the variations in material composition. The mechanism of flaw formation and the transformation of green sheet flaws into defects that appear in intermediate and finished sheet products are described. A mathematical model which describes the green sheet heat transfer propagation, in the context of the inspection technique and the compact heterogeneity, is also presented. The potential for feedback within the production process is also discussed

Changing stroke mortality trends in middle-aged people: an age-period-cohort analysis of routine mortality data in persons aged 40 to 69 in England

Background: In the UK, overall stroke mortality has declined. A similar trend has been seen in coronary heart disease, although recent reports suggest this decline might be levelling off in middle-aged adults. Aim: To investigate recent trends in stroke mortality among those aged 40–69 years in England. Methods: The authors used routine annual aggregated stroke death and population data for England for the years 1979–2005 to investigate time trends in gender-specific mortalities for adults aged 40 to 69 years. The authors applied log-linear modelling to isolate effects attributable to age, linear ‘drift’ over time, time period and birth cohort. Results; Between 1979 and 2005, age-standardised stroke mortality aged 40 to 69 years dropped from 93 to 30 per 100 000 in men and from 62 to 18 per 100 000 in women. Mortality was higher in older age groups, but the difference between the older and younger age groups appears to have decreased over time for both sexes. Modelling of the data suggests an average annual reduction in stroke deaths of 4.0% in men and 4.3% in women, although this decrease has been particularly marked in the last few years. However, we also observed a relative rate increase in mortality among those born since the mid-1940s compared with earlier cohorts; this appears to have been sustained in men, which explains the levelling off in the rate of mortality decline observed in recent years in the younger middle-aged. Conclusions: If observed trends in middle-aged adults continue, overall stroke mortalities may start to increase again

National Register of Historic Places Eligibility Testing of Site 41SM385 Within TxDOT\u27s Tyler District, Smith County, Texas

PBS&J, an Atkins company, was contracted by the North East Texas Regional Mobility Authority to conduct National Register of Historic Places eligibility testing of site 41SM385, a prehistoric campsite on a small rise above the floodplain of Indian Creek in western Smith County, Texas. Testing investigations were conducted during March and September 2009. The site was subjected to a systematic program of shovel testing, mechanical trenching, and hand excavation in an effort to identify cultural features or living surfaces and optimize recovery of diagnostic faunal, floral, and artifactual remains. The recovered cultural artifacts indicate that site 41SM385 represents a probable Woodland and Caddo‐aged occupation on a small rise on the creek floodplain. The Woodland component is based on recovered small Gary and Kent projectile points characteristic of Woodland culture of the region. The Caddo component is based on ceramic sherds of probable Early or Middle Caddo origin identified at the site. Radiocarbon dating of four ceramic sherds supports these assessments with three sherds dating to the Early to Middle Caddo periods and one sherd dating to the Woodland period. The lack of identified cultural features suggests that the Woodland component probably represents a series of ephemeral usages of the location, probably as short‐term campsites. The Caddo‐aged artifacts at the site probably represent a series of ephemeral usage of the location, either as a resource procurement locus ancillary to nearby site 41SM404 or as a short‐term campsite. The testing program failed to locate living surfaces or cultural features containing in situ artifactual or organic remains preserved on the site. The absence of cultural features and the paucity of lithic tools or ceramic remains make more‐meaningful functional interpretation infeasible. For this reason, the site lacks the data resources that would warrant National Register of Historic Places isting or designation as a State Archeological Landmark. No further work is recommended

The role of ECL2 in CGRP receptor activation: a combined modelling and experimental approach

The calcitonin gene-related peptide (CGRP) receptor is a complex of a calcitonin receptor-like receptor (CLR), which is a family B G-protein-coupled receptor (GPCR) and receptor activity modifying protein 1. The role of the second extracellular loop (ECL2) of CLR in binding CGRP and coupling to Gs was investigated using a combination of mutagenesis and modelling. An alanine scan of residues 271–294 of CLR showed that the ability of CGRP to produce cAMP was impaired by point mutations at 13 residues; most of these also impaired the response to adrenomedullin (AM). These data were used to select probable ECL2-modelled conformations that are involved in agonist binding, allowing the identification of the likely contacts between the peptide and receptor. The implications of the most likely structures for receptor activation are discussed.</jats:p

Technology Review of Nondestructive Methods for Examination of Water Intrusion Areas on Hanford’s Double-Shell Waste Tanks

Under a contract with CH2M Hill Hanford Group, Inc., PNNL has performed a review of the NDE technology and methods for examination of the concrete dome structure of Hanford’s double-shell tanks. The objective was to provide a matrix of methodologies that could be evaluated based on applicability, ease of deployment, and results that could provide information that could be used in the ongoing structural analysis of the tank dome. PNNL performed a technology evaluation with the objective of providing a critical literature review for all applicable technologies based on constraints provided by CH2M HILL. These constraints were not mandatory, but were desired. These constraints included performing the evaluation without removing any soil from the top of the tank, or if necessary, requesting that the hole diameter needed to gain access to evaluate the top of the tank structure to be no greater than approximately 12-in. in diameter. PNNL did not address the details of statistical sampling requirements as they depend on an unspecified risk tolerance. PNNL considered these during the technology evaluation and have reported the results in the remainder of this document. Many of the basic approaches to concrete inspection that were reviewed in previous efforts are still in use. These include electromagnetic, acoustic, radiographic, etc. The primary improvements in these tools have focused on providing quantitative image reconstruction, thus providing inspectors and analysts with three-dimensional data sets that allow for operator visualization of relevant abnormalities and analytical integration into structural performance models. Available instruments, such as radar used for bridge deck inspections, rely on post-processing algorithms and do not provide real-time visualization. Commercially available equipment only provides qualitative indications of relative concrete damage. It cannot be used as direct input for structural analysis to assess fitness for use and if necessary to de-rate critical components. There are currently no tools that automatically convert the NDE data to formats compatible with structural analysis programs. While radiographic techniques still provide significant advantages in spatial resolution, non-ionizing techniques are still preferred. Radar imagining in the 1–5 GHz has become the most useful. Unfortunately the algorithms and underlying assumptions used in these reconstructions are proprietary, and it is not possible to assess the quality and limitations of the analytical methods used to generate the derived structural data. The hypothesis that water intrusion may contribute to potential rebar corrosion of the tank domes provided the primary guidance in reviewing and evaluating available NDE technologies. Of primary concern is the need to employ technologies that provide the best opportunity for visualizing the rebar and providing quantitative data that can be integrated into structural analysis efforts to better understand and quantify the structural capacity of the domes. The conclusion is that an imaging system capable of locating and quantifying the distribution and conditions of the cement, aggregate, and rebar will provide the most valuable baseline upon which to build a case for the integrity of the structure. If successful, such a system would fulfill the need to incorporate valuable data into current structural load capacity analysis

High Resolution Imaging of Vascular Function in Zebrafish

Rationale: The role of the endothelium in the pathogenesis of cardiovascular disease is an emerging field of study, necessitating the development of appropriate model systems and methodologies to investigate the multifaceted nature of endothelial dysfunction including disturbed barrier function and impaired vascular reactivity. Objective: We aimed to develop and test an optimized high-speed imaging platform to obtain quantitative real-time measures of blood flow, vessel diameter and endothelial barrier function in order to assess vascular function in live vertebrate models. Methods and Results: We used a combination of cutting-edge optical imaging techniques, including high-speed, camera-based imaging (up to 1000 frames/second), and 3D confocal methods to collect real time metrics of vascular performance and assess the dynamic response to the thromboxane A2 (TXA2) analogue, U-46619 (1 μM), in transgenic zebrafish larvae. Data obtained in 3 and 5 day post-fertilization larvae show that these methods are capable of imaging blood flow in a large (1 mm) segment of the vessel of interest over many cardiac cycles, with sufficient speed and sensitivity such that the trajectories of individual erythrocytes can be resolved in real time. Further, we are able to map changes in the three dimensional sizes of vessels and assess barrier function by visualizing the continuity of the endothelial layer combined with measurements of extravasation of fluorescent microspheres. Conclusions: We propose that this system-based microscopic approach can be used to combine measures of physiologic function with molecular behavior in zebrafish models of human vascular disease. © 2012 Watkins et al

Evaluation of an ambulatory system for the quantification of cough frequency in patients with chronic obstructive pulmonary disease

BACKGROUND: To date, methods used to assess cough have been primarily subjective, and only broadly reflect the impact of chronic cough and/or chronic cough therapies on quality of life. Objective assessment of cough has been attempted, but early techniques were neither ambulatory nor feasible for long-term data collection. We evaluated a novel ambulatory cardio-respiratory monitoring system with an integrated unidirectional, contact microphone, and report here the results from a study of patients with COPD who were videotaped in a quasi-controlled environment for 24 continuous hours while wearing the ambulatory system. METHODS: Eight patients with a documented history of COPD with ten or more years of smoking (6 women; age 57.4 ± 11.8 yrs.; percent predicted FEV(1 )49.6 ± 13.7%) who complained of cough were evaluated in a clinical research unit equipped with video and sound recording capabilities. All patients wore the LifeShirt(® )system (LS) while undergoing simultaneous video (with sound) surveillance. Video data were visually inspected and annotated to indicate all cough events. Raw physiologic data records were visually inspected by technicians who remained blinded to the video data. Cough events from LS were analyzed quantitatively with a specialized software algorithm to identify cough. The output of the software algorithm was compared to video records on a per event basis in order to determine the validity of the LS system to detect cough in COPD patients. RESULTS: Video surveillance identified a total of 3,645 coughs, while LS identified 3,363 coughs during the same period. The median cough rate per patient was 21.3 coughs·hr(-1 )(Range: 10.1 cghs·hr(-1 )– 59.9 cghs·hr(-1)). The overall accuracy of the LS system was 99.0%. Overall sensitivity and specificity of LS, when compared to video surveillance, were 0.781 and 0.996, respectively, while positive- and negative-predictive values were 0.846 and 0.994. There was very good agreement between the LS system and video (kappa = 0.807). CONCLUSION: The LS system demonstrated a high level of accuracy and agreement when compared to video surveillance for the measurement of cough in patients with COPD

Factorized Q-Learning for Large-Scale Multi-Agent Systems

Deep Q-learning has achieved significant success in single-agent decision making tasks. However, it is challenging to extend Q-learning to large-scale multi-agent scenarios, due to the explosion of action space resulting from the complex dynamics between the environment and the agents. In this paper, we propose to make the computation of multi-agent Q-learning tractable by treating the Q-function (w.r.t. state and joint-action) as a high-order high-dimensional tensor and then approximate it with factorized pairwise interactions. Furthermore, we utilize a composite deep neural network architecture for computing the factorized Q-function, share the model parameters among all the agents within the same group, and estimate the agents' optimal joint actions through a coordinate descent type algorithm. All these simplifications greatly reduce the model complexity and accelerate the learning process. Extensive experiments on two different multi-agent problems demonstrate the performance gain of our proposed approach in comparison with strong baselines, particularly when there are a large number of agents.Comment: 7 pages, 5 figures, DAI 201

Endometrial Tumor Classification by Histomorphology and Biomarkers in the Nurses’ Health Study

Objective: Endometrial cancers have historically been classified by histomorphologic appearance, which is subject to interobserver disagreement. As molecular and biomarker testing has become increasingly available, the prognostic significance and accuracy of histomorphologic diagnoses have been questioned. To address these issues for a large, prospective cohort study, we provide the results of a centralized pathology review and biomarker analysis of all incidental endometrial carcinomas occurring between 1976 and 2012 in the Nurses' Health Study. Methods: Routine histology of all (n = 360) cases was reviewed for histomorphologic diagnosis. Cases were subsequently planted in a tissue microarray to explore expression of a variety of biomarkers (e.g., ER, PR, p53, PTEN, PAX2, AMACR, HNF1β, Napsin A, p16, PAX8, and GATA3). Results: Histologic subtypes included endometrioid (87.2%), serous (5.6%), carcinosarcoma (3.9%), clear cell (1.7%), and mixed type (1.7%). Biomarker results within histologic subtypes were consistent with existing literature: abnormal p53 was frequent in serous cases (74%), and HNF1β (67%), Napsin A (67%), and AMACR (83%) expression was frequent in clear cell carcinomas. Our dataset also allowed for examination of biomarker expression across non-preselected histologies. The results demonstrated that (1) HNF1β was not specific for clear cell carcinoma, (2) TP53 mutations occurred across many histologies, and (3) GATA3 was expressed across multiple histotypes, with 75% of positive cases demonstrating high-grade features. Conclusions: Our findings establish the subtypes of endometrial cancer occurring in the Nurses' Health Study, corroborate the sensitivity of certain well-established biomarkers, and call into question previously identified associations between certain biomarkers (e.g., HNF1B) and particular histotypes