Measurement of Dynamic Temperatures and Pressures in Nuclear Power Plants

The dynamic response of the process sensors that supply real-time data to the safety systems in nuclear power plants (NPP) play a vital role in preventing plant accidents. If a critical process temperature, pressure, level, or flow experiences a step change, for example, the sensors that measure the process variable must act quickly to actuate the safety systems that will mitigate the consequence of an undesirable process excursion. The research conducted for this dissertation has been performed to ensure the prompt response of critical sensors by advancing, refining, validating, and implementing new methods for measuring the response time of temperature, pressure, level, and flow sensors in NPP safety systems. The essential significance of the new methods is that they can be performed remotely on installed sensors at operating conditions, thereby providing the actual in-service response time as opposed to the unrealistic response time provided by the manufacturer or by offline testing. The in-situ response time testing technique for temperature sensors is referred to as the Loop Current Step Response (LCSR) test. This technique is based on heating the sensor internally by applying a step change in the DC current to the sensor extension leads in the plant control room. The DC current heats the sensing element of the sensor, resulting in a temperature transient that is then analyzed to provide a true sensor response time, which accounts for all process conditions as well as for the effects of installation and aging. This dissertation presents the theoretical foundation of the LCSR, the details of the author’s extensive experimental research to validate and refine its use in multiple nuclear plant safety applications, and the assumptions that support the validity of the author’s research and experimental results. The in-situ response time testing technique for pressure, level, and flow transmitters is the so-called noise analysis method. This method is based on recording and analyzing the inherent process fluctuations present at the output of transmitters while the plant is operating. These fluctuations (noise) arise from random flux, turbulent flow, random heat transfer, process control action, and vibration. They are separated from the output of the transmitter by signal conditioning, recorded for about an hour, and analyzed in frequency and/or time domain to yield the response time of the pressure sensing system. This dissertation describes the theoretical foundation of the noise analysis technique, the details of the experimental research that the author has conducted for this dissertation to validate and expand the scope of this technique in actual plant applications, and the assumptions informing the author’s confidence that the research in this dissertation validates the noise analysis technique. The significance of the noise analysis technique is that it not only measures the in-service response time of the transmitter but also of its sensing lines. In contrast to other methods, it can thereby account for the effect of sensing-line length, blockages, and voids on sensor response time. As part of this research, both the LCSR and noise analysis techniques were validated through extensive laboratory measurements performed on temperature and pressure sensors of the types used in nuclear power plants. The author has used these results to indicate where these methods are most effective but also where they may pose significant uncertainties or may fail

Reparameterization of ruled surfaces: toward generating smooth jerk-minimized toolpaths for multi-axis flank CNC milling

This paper presents a novel jerk minimization algorithm in the context of multi-axis flank CNC machining. The toolpath of the milling axis in a flank milling process, a ruled surface, is reparameterized by a B-spline function, whose control points and knot vector are unknowns in an optimization-based framework. The total jerk of the tool's motion is minimized, implying the tool is moving as smooth as possible, without changing the geometry of the given toolpath. Our initialization stage stems from measuring the ruling distance metric (RDM) of the ruled surface. We show on several examples that this initialization reliably finds close initial guesses of jerk-minimizers and is also computationally efficient. The applicability of the presented approach is illustrated by some practical case studies.RYC-2017-2264

Adjustment formulae to improve the correlation of white-to-white measurement with direct measurement of the ciliary sulcus diameter by ultrasound biomicroscopy

Purpose: This study evaluates the correlation between horizontal white-to-white (WTW) distance using Caliper and Orbscan IIz with the ciliary sulcus diameter measured by high frequency ultrasound biomicroscopy (UBM) and presents an adjustment formula to improve the correlation. Methods: We measured horizontal sulcus-to-sulcus (STS) dimension of 273 right eyes of 273 high myopic patients with 35 MHz UBM and horizontal WTW using Orbscan IIz and Caliper. Mean WTW diameter, differences, and the correlation of measurement methods were evaluated. Results: The mean spherical equivalent was �8.79 ± 4.87 diopters. Mean horizontal STS dimension with UBM was 12.13 ± 0.45 mm (range, 10.81�13.42 mm). Mean WTW diameter in the Caliper method was 11.70 ± 0.40 mm (range, 10.6�12.8 mm) and 11.70 ± 0.40 mm (range, 10.5�13.1 mm) in the Orbscan method. Mean difference of UBM STS and WTW with Caliper was 0.48 ± 0.28 mm (range, �0.19 to 1.37 mm). Mean difference of UBM STS diameter and Orbscan WTW was 0.38 ± 0.31 mm (range, �0.64 to 1.29 mm). The Pearson correlations of WTW diameter measured by Caliper and Orbscan with UBM's STS diameter were 0.778 and 0.773, respectively. This difference diminished after adjustment. The 95 limit of agreement was almost the same in Caliper and Orbscan (�0.07 to 1.03 compared with �0.23 to 0.99). Conclusion: There is a significant difference in measurements between STS diameter using UBM and WTW diameter utilizing Caliper and Orbscan. This difference diminished after our recommended adjustment. © 2017 Iranian Society of Ophthalmolog

New instrumentation technologies for testing the bonding of sensors to solid materials

This report presents the results of a comprehensive research and development project that was conducted over a three-year period to develop new technologies for testing the attachment of sensors to solid materials for the following NASA applications: (1) testing the performance of composites that are used for the lining of solid rocket motor nozzles, (2) testing the bonding of surface-mounted platinum resistance thermometers that are used on fuel and oxidizer lines of the space shuttle to detect valve leaks by monitoring temperature, (3) testing the attachment of strain gages that are used in testing the performance of space shuttle main engines, and (4) testing the thermocouples that are used for determining the performance of blast tube liner material in solid rocket boosters

Solving boundary value problems via the Nyström method using spline Gauss rules

We propose to use spline Gauss quadrature rules for solving boundary value problems (BVPs) using the Nyström method. When solving BVPs, one converts the corresponding partial differential equation inside a domain into the Fredholm integral equation of the second kind on the boundary in the sense of boundary integral equation (BIE). The Fredholm integral equation is then solved using the Nyström method, which involves the use of a particular quadrature rule, thus, converting the BIE problem to a linear system. We demonstrate this concept on the 2D Laplace problem over domains with smooth boundary as well as domains containing corners. We validate our approach on benchmark examples and the results indicate that, for a fixed number of quadrature points (i.e., the same computational effort), the spline Gauss quadratures return an approximation that is by one to two orders of magnitude more accurate compared to the solution obtained by traditional polynomial Gauss counterparts

Solving Boundary Value Problems Via the Nyström Method Using Spline Gauss Rules

We propose to use spline Gauss quadrature rules for solving boundary value problems (BVPs) using the Nyström method. When solving BVPs, one converts the corresponding partial differential equation inside a domain into the Fredholm integral equation of the second kind on the boundary in the sense of boundary integral equation (BIE). The Fredholm integral equation is then solved using the Nyström method, which involves a use of a particular quadrature rule, thus, converting the BIE problem to a linear system. We demonstrate this concept on the 2D Laplace problem over domains with smooth boundary as well as domains containing corners. We validate our approach on benchmark examples and the results indicate that, for a fixed number of quadrature points (i.e., the same computational effort), the spline Gauss quadratures return an approximation that is by one to two orders of magnitude more accurate compared to the solution obtained by traditional polynomial Gauss counterparts

Autism Spectrum Disorders Diagnosing Based on EEG Analysis: a Survey

Autism spectrum disorders (ASD) are pervasive neurodevelopmental conditions characterized by impairments in reciprocal social interactions, communication skills, and stereotyped behavior. Since EEG recording and analysis is one of the fundamental tools in diagnosis and identifying disorders in neurophysiology, researchers strive to use the EEG signals for diagnosing of individuals with ASD. We found that studies on the ASD diagnosis using EEG techniques could be divided into two groups, where analysis was based on either comparison techniques or pattern recognition techniques. In this paper, we try to explain these two sets of algorithms along with their applied methods and results. Ultimately, evaluation measures of diagnosis algorithms are discussedРозлади аутистичного спектра (autism spectrum disorders – ASD) – це глибокі відхилення розвитку нервової сфери, що характеризуються порушенням соціальних взаємодій, комунікативних навичок та стереотипної поведінки. Оскільки реєстрація та аналіз ЕЕГ є одними із фундаментальних засобів діагностики та ідентифікації нейрофізіологічних розладів, дослідники намагаються використовувати ЕЕГ-сигнали для діагностики ASD у тих або інших осіб. Як ми встановили, дослідження, спрямовані на діагностику ASD із застосуванням ЕЕГ-методик, можуть бути поділені на дві групи, коли аналіз базується або на техніці порівнянь, або на техніці розпізнавання образів. У цьому огляді ми намагались описати застосування двох відповідних комплексів алгоритмів, а також методики їх використання та отримані результати. Нарешті, обговорюється порівняльна ефективність вказаних алгоритмів діагностування

After Kosovo: a political science symposium - perspectives from Southern Italy

"Im Mai 1999 veranstalteten eine Gruppe von Forschern und Kursteilnehmern des Arbeitsbereiches Politik- und Sozialwissenschaften sowie einige Kollegen aus anderen Ländern zum dritten Mal ein Symposium im malerischen Dorf Positano (Süditalien). Auf der Tagesordnung beim diesjährigen Treffen stand das für einen Politikwissenschaftler vorrangige Thema jener Wochen: die militärischen, politischen und kulturellen Geschehnisse im Kosovo. Die Teilnehmer überdachten 15 Fragen hinsichtlich der Kosovo-Krise, oder genauer, die Konsequenzen jener Geschehnisse für die politische Wissenschaft. Das Ziel dieses Beitrages ist es, die spontanen Gedanken zu diesen Fragen aufzuzeichnen. Trotz unterschiedlicher Meinungen und Erklärungsansätze gelang es den Teilnehmern, die wesentlichen Konsequenzen aus diesem Konflikt, der viel mehr war als eine Balkan-Krise, herauszuarbeiten. So muß die politische Rolle der deutschen und russischen Akteure neu überdacht werden. Das Möglichkeit militärischer Missionen und die Option für westlichen Gesellschaften, einen Krieg zu führen, müssen neu bewertet werden. Sowohl der sogenannte neue internationale Auftrag als auch die veränderte Rolle der UNO sowie das westfälische Prinzip der Staatensouveränität müssen neu diskutiert werden. Der vielleicht interessanteste Aspekt ist die Frage nach der politischen Improvisation sowie die Frage nach virtuellen Politiken und das Fehlen einer politischen Agenda." (Textauszug)"In May 1999, a group of researchers and students from the Department of Political and Social Sciences and some colleagues from other countries got together for the third time in the picturesque Campanian village of Positano. The context of this year's meeting, the public discussions made it unavoidable to take up the most urgent subject for political scientists in those weeks: the military, political and cultural events in and around Kosovo. The participants got some 15 questions regarding the Kosovo crisis or rather, more exactly, regarding possible consequences of the events for political science. The aim of this paper, however, was to preserve the spontaneous character of the original inputs. While stressing different aspects and advancing various explanations, most participants of Horizons 1999 agreed in a remarkable way on some fundamental consequences of this conflict which was much more than a Balkan crisis. German and Russian actors' role and impact have to be reassessed. The future potential of military missions and the capability of Western societies to wage war must be re-evaluated. The so-called new international order -or disorder- is to be discussed, as well as the changing role of the UN and the Westphalian principle of sovereignty. The possibly most interesting aspects may be related to the questions of adhocism, virtual politics and missing agendas, possibly leading towards a new conception of agency." (extract