Data-driven analysis of ultrasonic pressure tube inspection data

Pressure tubes are critical components of the CANDU reactors and other pressurized heavy water type reactors, as they contain the nuclear fuel and the coolant. Manufacturing flaws, as well as defects developed during the in-service operation, can lead to coolant leakage and can potentially damage the reactor. The current inspection process of these flaws is based on manually analyzing ultrasonic data received from multiple probes during planned, statutory outages. Recent advances on ultrasonic inspection tools enable the provision of high resolution data of significantly large volumes. This is highlighting the need for an efficient autonomous signal analysis process. Typically, the automation of ultrasonic inspection data analysis is approached by knowledge-based or supervised data-driven methods. This work proposes an unsupervised data-driven framework that requires no explicit rules, nor individually labeled signals. The framework follows a two-stage clustering procedure that utilizes the DBSCAN density-based clustering algorithm and aims to provide decision support for the assessment of potential defects in a robust and consistent way. Nevertheless, verified defect dimensions are essential in order to assess the results and train the framework for unseen defects. Initial results of the implementation are presented and discussed, with the method showing promise as a means of assessing ultrasonic inspection data

Judges as Students of American Society

Symposium: The Writing of Judicial Biography American Political Science Association, Chicago, December 28-30, 194

Prehistory of Transit Searches

Nowadays the more powerful method to detect extrasolar planets is the transit method. We review the planet transits which were anticipated, searched, and the first ones which were observed all through history. Indeed transits of planets in front of their star were first investigated and studied in the solar system. The first observations of sunspots were sometimes mistaken for transits of unknown planets. The first scientific observation and study of a transit in the solar system was the observation of Mercury transit by Pierre Gassendi in 1631. Because observations of Venus transits could give a way to determine the distance Sun-Earth, transits of Venus were overwhelmingly observed. Some objects which actually do not exist were searched by their hypothetical transits on the Sun, as some examples a Venus satellite and an infra-mercurial planet. We evoke the possibly first use of the hypothesis of an exoplanet transit to explain some periodic variations of the luminosity of a star, namely the star Algol, during the eighteen century. Then we review the predictions of detection of exoplanets by their transits, those predictions being sometimes ancient, and made by astronomers as well as popular science writers. However, these very interesting predictions were never published in peer-reviewed journals specialized in astronomical discoveries and results. A possible transit of the planet beta Pic b was observed in 1981. Shall we see another transit expected for the same planet during 2018? Today, some studies of transits which are connected to hypothetical extraterrestrial civilisations are published in astronomical refereed journals. Some studies which would be classified not long ago as science fiction are now considered as scientific ones.Comment: Submiited to Handbook of Exoplanets (Springer

Nutrient export in run-off from an in-field cattle overwintering site in east-central Saskatchewan

Non-Peer Reviewe

Lactate Regulates Metabolic and Proinflammatory Circuits in Control of T Cell Migration and Effector Functions

Licensed by the Creative Commons Attribution Licens

Alternative Pasture Development System and Breeding Weight for Beef Heifers

Proper development of replacement beef heifers is critical and needs to be accomplished at lower costs without sacrificing reproductive performance. The current recommendations indicate heifers should reach approximately 65% of mature body weight (MBW) at breeding for successful reproduction (Patterson et al. 1992; NRC 1996). Meeting heifer maintenance and gestation nutrient requirements are getting more economically challenged for beef producers in western Canada. Therefore, producers are moving from drylot development systems where cattle are housed and fed in pens to the adoption of extensive grazing systems (Kelln et al. 2011) in field paddocks. Limited research has been conducted to determine whether inherent differences in development systems affect reproductive efficiency of heifers. The most commonly used extensive dormant season grazing system in western Canada is pasture grazing forage bales in field paddocks (Kelln et al. 2011). The objectives of this study were to determine: (1) the effects of developing heifers to a pre-breeding targeted body weight (BW) of either 55 or 62% MBW on dry matter intake (DMI), nutrient intake and reproductive efficiency; and (2) the effects of developing heifers in either field pasture paddocks (PG) or conventional drylot pens (DL) on development system cost over 2 seasons (2010-2012)