Traveling Wave Response in Full-Scale Drilling Riser VIV Measurements

2011 ◽  
Author(s):  
Hayden Marcollo ◽  
Adrian Eassom ◽  
Emmanuel Fontaine ◽  
Michael Tognarelli ◽  
Pierre Beynet ◽  
...  
Keyword(s):  
Standing Wave ◽  
Traveling Wave ◽  
Angular Rate ◽  
Structural Response ◽  
Full Scale ◽  
Loop Current ◽  
The Novel ◽  
Novel Methods ◽  
High Level ◽  
First Time

The dominance of traveling wave VIV response is observed in full-scale measured drilling riser data for the first time. This paper presents the novel methods developed to identify the presence of traveling versus standing wave riser structural response in the full-scale data and the observations. This paper reports on some of the work conducted under the most recently completed phase of the DeepStar JIP (Phase 9). The paper uses four different novel methods to identify the presence of traveling versus standing wave structural response in data obtained from a full-scale Gulf of Mexico drilling riser during a loop current event. The techniques are: 1) Observation of RMS accelerations between synchronized accelerometers; 2) Observation of filtered displacements between synchronized accelerometers (using a new postprocessing synchronization technique); 3) Displacement versus angular rate phase diagrams; and 4) Derivation of upward/downward curvature components via an algorithm proposed by two of the co-authors. High level conclusions are drawn about the structural response types. Recommendations for future instrumentation campaigns are made.

Efficient Modal Decomposition and Reconstruction of Riser Response due to VIV

2011 ◽  
Author(s):  
S. I. McNeill ◽  
P. Agarwal
Keyword(s):  
Fatigue Damage ◽  
Traveling Wave ◽  
Angular Rate ◽  
Normal Modes ◽  
Structural Response ◽  
Measured Data ◽  
Vibration Monitoring ◽  
Wave Number ◽  
Modal Decomposition ◽  
Basis Vectors

Vortex-Induced-Vibrations (VIV) due to ocean currents can consume a sizable portion of the allotted fatigue life of marine risers. Vibration monitoring and concurrent estimation of fatigue damage due to VIV can significantly enhance the safe and reliable operation of risers. To this end, riser response can be characterized by using sensors (e.g. accelerometers and/or angular rate sensors) to measure the motion of the riser at a few locations. Fatigue damage can be predicted along the entire length of riser from measured data using the method of modal decomposition and reconstruction. In this method the structural response of interest, such as stress and fatigue damage, is expressed by modal superposition, where the modal weights are estimated using measured data and analytical modeshapes. However the accuracy of this method declines as the sensor density (number of sensors per unit riser length) decreases, especially when the riser vibrates in high-order modes and exhibits traveling wave behavior. In this paper, an efficient frequency-domain methodology allowing for accurate reconstruction of the riser response along the entire riser using a limited number of sensors is proposed. We first identify the excited VIV modes (natural frequency and modeshape) using principal vectors of the cross spectral density. Modal decomposition and reconstruction is performed separately for each VIV band surrounding each excited mode. This allows us to use several (as many as the number of sensors) participating modes in each band, and thus improve the accuracy. Since the stress distribution is sensitive to the chosen set of participating modes, we optimize over several candidate sets, selecting the set of modes that result in the lowest prediction error. In order to improve the reconstruction of complex modes, particularly traveling waves, the modeshapes can be augmented with additional basis vectors. The additional basis vectors are obtained by shifting the phase of the normal modes by 90 degrees at every wave number using the Hilbert transform. Though developed in the context of VIV, the method can be used to estimate fatigue damage due to vibrations regardless of the excitation mechanism. The methodology is demonstrated using the NDP (Norwegian Deepwater Program) test data on a 38 meter long slender riser, using data from eight accelerometers. Results show that the proposed algorithm can reconstruct stresses and fatigue damage accurately along the length of the riser in the presence of traveling wave behavior using relatively few sensors.

scholarly journals The Importance of Building Community Trust for Sustained Malaria Elimination Interventions During Unforeseen Major Disruptive Events Such as COVID-19: A Cambodia Case Study

2020 ◽  
Author(s):  
Mitra Feldman ◽  
Lieven Vernaeve ◽  
James Tibenderana ◽  
Leo Braack ◽  
Mark Debackere ◽  
...  
Keyword(s):  
Rural Communities ◽  
Malaria Elimination ◽  
The Novel ◽  
National Guidelines ◽  
Patients At Risk ◽  
Building Community ◽  
Novel Coronavirus ◽  
High Level ◽  
First Time

Abstract Background Impressive progress in reducing malaria trends combined with the 2018 report of no malaria related deaths for the first time, puts Cambodia well on track to reaching its malaria elimination goals. However, the novel coronavirus SARS-CoV-2 (COVID-19) pandemic presents a potential challenge to this goal. The path towards malaria elimination is dependent on sustained interventions to prevent rapid resurgence, which can quickly set back any gains achieved. Methods Mobile Malaria Workers (MMWs) need to have a strong understanding of the local geography and, most importantly, build and maintain trust among the communities they serve. To achieve this, Malaria Consortium uses a peer-to-peer approach for the MMWs and ensures the same level of trust operates between the MMWs and Malaria Consortium. Malaria Consortium’s policy during COVID-19 has been to follow national guidelines while continuing to support community-based malaria services via the MMWs / mobile malaria posts (MPs) with as minimal disruption as possible. A risk assessment was carried out by Malaria Consortium, with a mitigation plan quickly developed and implemented, to ensure MMWs were able to continue providing services without putting themselves or their patients at risk. Results Malaria Consortium ensured the MMW/ mobile MP program is built on trust, relevance to, and connection with the communities being served. An overall decline in malaria testing was reported from Health Centres and VMWs among all three provinces in March and April, not seen in previous years and possibly attributable to fear of COVID-19. However, Malaria Consortium supported MMWs have not reported any such decline in the utilization of their services and attribute this to the trust they have among the communities. Conclusion Malaria Consortium has effectively demonstrated care and solidarity with and among the MMWs and communities being served. This has ensured a high level of trust, and therefore willingness among the MMWs and communities to continue providing and utilising malaria services as usual despite the fear of COVID-19. Building trust among rural communities builds resilience and ensures uninterrupted and effective malaria elimination activities can continue even during a potential extraneous disruptive force, such as the Covid-19 pandemic.

scholarly journals THE INFLUENCE OF F. M. DOSTOEVSKY’S NOVEL “CRIME AND PUNISHMENT” ON THE WORKS OF VIETNAMESE WRITERS

2021 ◽  
pp. 60-67
Author(s):  
Тхи Хоан Нгуен
Keyword(s):  
General Idea ◽  
The Novel ◽  
Cultural Space ◽  
Crime And Punishment ◽  
Foreign Literature ◽  
Russian Novel ◽  
Special Place ◽  
History Of ◽  
High Level ◽  
First Time

В статье впервые дано общее представление о влиянии «Преступления и наказания» Ф. М. Достоевского на творчество вьетнамских писателей на протяжении целого столетия. Автор обращает внимание, что роман «Преступление и наказание» занимает особое место в культурном пространстве Вьетнама, оказывая влияние на поэтику художественных произведений вьетнамских прозаиков, их мировоззренческие и эстетические ориентиры. В работе наглядно иллюстрируется процесс вхождения «Преступления и наказания» в культуру Вьетнама, который шел через творческую адаптацию романа. Автор отмечает, что сложные философские проблемы, которые поднимались в романе Ф. М. Достоевского, вызывали большой интерес у вьетнамских читателей, а у ряда вьетнамских писателей и стремление к подражанию. Исследование показало, что «Преступление и наказание» оказало заметное влияние не только на сюжет, идею художественных произведений, но и на языковой стиль многих известных вьетнамских романистов в ходе модернизации вьетнамской литературы. Интерес к роману великого русского писателя сохраняется сегодня на высоком уровне, что способствует развитию культурных связей между двумя народами. В статье делается вывод о незаменимой позиции романа «Преступление и наказание» в сердцах вьетнамских читателей. Научная новизна настоящего исследования определяется изучением творческой адаптации романа Ф. М. Достоевского в литературной практике вьетнамских художников слова на протяжении XX-XXI веков, а также обозначением различных линий в рецепции известного русского романа во Вьетнаме. Результаты исследования могут быть использованы на занятиях по истории русской и зарубежной литератур, будут интересны учителям-словесникам, а также всем увлеченным художественной литературой и культурой. The article for the first time gives a general idea of the influence of “Crime and Punishment” by F. M. Dostoevsky on the works of Vietnamese writers for a whole century. The author observes that the novel “Crime and Punishment” occupies a special place in the cultural space of Vietnam, influencing the poetics of the artistic works of Vietnamese prose writers, their ideological and aesthetic guidelines. The work clearly illustrates the process by which “Crime and Punishment” enters into the culture of Vietnam, which went through the creative adaptation of the novel. The author notes that the complex philosophical problems that were raised in the novel by F. M. Dostoevsky aroused great interest among Vietnamese readers, and a number of Vietnamese writers also had a desire to imitate. The study showed that “Crime and Punishment” had a noticeable impact not only on the plot, the idea of literary works, but also on the language style of many famous Vietnamese novelists during the modernization of Vietnamese literature. Interest in the novel of the great Russian writer remains today at a high level, which contributes to the development of cultural ties between the two peoples. The article concludes about the irreplaceable position of the novel “Crime and Punishment” in the hearts of Vietnamese readers. The scientific novelty of this study is determined by the study of the creative adaptation of the novel by F. M. Dostoevsky in the literary practice of Vietnamese authors during the 20th-21st centuries, as well as the designation of various lines in the reception of the famous Russian novel in Vietnam. The results of the research can be used in classes on the history of Russian and foreign literature, and will be of interest to teachers of literature as well as to all those who are interested in fiction and culture.

scholarly journals The importance of building community trust for sustained health interventions during disruptive events such as COVID-19: A Cambodia case study

2020 ◽  
Author(s):  
Mitra Feldman ◽  
Lieven Vernaeve ◽  
James Tibenderana ◽  
Mark Debackere ◽  
Leo Braack ◽  
...  
Keyword(s):  
Rural Communities ◽  
Malaria Elimination ◽  
Mitigation Measures ◽  
The Novel ◽  
National Guidelines ◽  
Building Community ◽  
Novel Coronavirus ◽  
High Level ◽  
First Time

Abstract Cambodia has made impressive progress in reducing malaria trends and, in 2018, reported no malaria related deaths for the first time. However, the novel coronavirus SARS-CoV-2 (COVID-19) pandemic presents a potential challenge to the country’s goal for malaria elimination by 2025. The path towards malaria elimination is dependent on sustained interventions to prevent rapid resurgence, which can quickly set back any gains achieved. Malaria Consortium supported Mobile Malaria Workers (MMWs) engage with target communities to promote acceptance, trust, and resilience. During the COVID-19 pandemic Malaria Consortium’s policy has been to follow national guidelines while continuing to support community-based malaria services via the MMWs / mobile malaria posts (MPs) with as minimal disruption as possible. A COVID-19 risk assessment was carried out by Malaria Consortium, with a mitigation plan quickly developed and implemented, to ensure MMWs were able to continue providing services without putting themselves or their patients at risk.In general, Health Centres and village malaria workers at District level saw an overall decline in malaria testing in March and April; however, Malaria Consortium-supported MMWs did not report any such decline in the utilization of their services. They attribute this to the trust they have among the communities especially regarding Covid-19 mitigation measures that were implemented, and their consequent ability to continue working safely thanks to Malaria Consortium’s rapid response and continued support.By effectively demonstrating care and solidarity with and among the MMWs and communities being served, the rapid and effective Covid-19 mitigation measures and community messaging have ensured a high level of trust, and therefore willingness to continue providing and utilising malaria services as usual, despite the fear of COVID-19. By building trust among rural communities, resilience was strengthened, and effective malaria elimination activities were able to continue uninterrupted, even during an extraneous disruptive force such as the Covid-19 pandemic.

A Confrontation between Two Doctrines: The Birth of Struggle for Hegemony in Hebrew Children's Literature during the 1930s and 1940s

2008 ◽  
Vol 1 (2) ◽  
pp. 139-155 ◽  
Author(s):  
YAEL DARR
Keyword(s):  
Children's Literature ◽  
Educational System ◽  
Single Channel ◽  
Children’S Literature ◽  
The Political ◽  
Literary Creation ◽  
History Of ◽  
High Level ◽  
First Time ◽  
Literary Quality

This article describes a crucial and fundamental stage in the transformation of Hebrew children's literature, during the late 1930s and 1940s, from a single channel of expression to a multi-layered polyphony of models and voices. It claims that for the first time in the history of Hebrew children's literature there took place a doctrinal confrontation between two groups of taste-makers. The article outlines the pedagogical and ideological designs of traditionalist Zionist educators, and suggests how these were challenged by a group of prominent writers of adult poetry, members of the Modernist movement. These writers, it is argued, advocated autonomous literary creation, and insisted on a high level of literary quality. Their intervention not only dramatically changed the repertoire of Hebrew children's literature, but also the rules of literary discourse. The article suggests that, through the Modernists’ polemical efforts, Hebrew children's literature was able to free itself from its position as an apparatus controlled by the political-educational system and to become a dynamic and multi-layered field.

Buried Narratives: Exhuming the Mother's Story in Oliver Twist

2018 ◽  
Vol 8 (3) ◽  
pp. 247-266
Author(s):  
Michelle L. Wilson
Keyword(s):  
Social Change ◽  
Maternal Inheritance ◽  
The Novel ◽  
Poor Law ◽  
The Family ◽  
The Law ◽  
First Time ◽  
Critical Consideration

Initially, Oliver Twist (1839) might seem representative of the archetypal male social plot, following an orphan and finding him a place by discovering the father and settling the boy within his inheritance. But Agnes Fleming haunts this narrative, undoing its neat, linear transmission. This reconsideration of maternal inheritance and plot in the novel occurs against the backdrop of legal and social change. I extend the critical consideration of the novel's relationship to the New Poor Law by thinking about its reflection on the bastardy clauses. And here, of course, is where the mother enters. Under the bastardy clauses, the responsibility for economic maintenance of bastard children was, for the first time, legally assigned to the mother, relieving the father of any and all obligation. Oliver Twist manages to critique the bastardy clauses for their release of the father, while simultaneously embracing the placement of the mother at the head of the family line. Both Oliver and the novel thus suggest that it is the mother's story that matters, her name through which we find our own. And by containing both plots – that of the father and the mother – Oliver Twist reveals the violence implicit in traditional modes of inheritance in the novel and under the law.

Application of Novel Low Current OBIRCH Amplifier and Nanoprobing to Identify Subtle Leakages in Advanced Node Technologies

2018 ◽  
Author(s):  
Satish Kodali ◽  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chong Khiam Oh
Keyword(s):  
Signal To Noise Ratio ◽  
Semiconductor Industry ◽  
Fault Isolation ◽  
Ring Oscillator ◽  
High Signal ◽  
The Novel ◽  
Resistance Change ◽  
Three Samples ◽  
Relative Threshold ◽  
First Time

Abstract Optical beam induced resistance change (OBIRCH) is a very well-adapted technique for static fault isolation in the semiconductor industry. Novel low current OBIRCH amplifier is used to facilitate safe test condition requirements for advanced nodes. This paper shows the differences between the earlier and novel generation OBIRCH amplifiers. Ring oscillator high standby leakage samples are analyzed using the novel generation amplifier. High signal to noise ratio at applied low bias and current levels on device under test are shown on various samples. Further, a metric to demonstrate the SNR to device performance is also discussed. OBIRCH analysis is performed on all the three samples for nanoprobing of, and physical characterization on, the leakage. The resulting spots were calibrated and classified. It is noted that the calibration metric can be successfully used for the first time to estimate the relative threshold voltage of individual transistors in advanced process nodes.

Rhythmic Prose in Imperial Greek Literature

2018 ◽  
Author(s):  
G. O. Hutchinson
Keyword(s):  
The Novel ◽  
Greek Literature ◽  
System A ◽  
First Time

The chapter looks at the division between poetry and prose in ancient and other literatures, and shows the importance of rhythmic patterning in ancient prose. The development of rhythmic prose in Greek and Latin is sketched, the system explained and illustrated (from Latin). It is firmly established, for the first time, which of the main Greek non-Christian authors 31 BC–AD 300 write rhythmically. The method takes a substantial sample of random sentence-endings (usually 400) from each of a large number of Imperial authors; it compares that sample with one sample of the same size (400) drawn randomly from a range of authors earlier than the invention of this rhythmic system. A particular sort of X2-test is applied. Many Imperial authors, it emerges, write rhythmically; many do not. The genres most likely to offer rhythmic writing are, unexpectedly, narrative: historiography and the novel.

Kidnapped

2014 ◽  
Author(s):  
Robert Louis Stevenson ◽  
Ian Duncan
Keyword(s):  
West Coast ◽  
Historical Novel ◽  
The Novel ◽  
The West ◽  
Scottish Highlands ◽  
Cross Country ◽  
First Time ◽  
Adventure Stories

Your bed shall be the moorcock’s, and your life shall be like the hunted deer’s, and ye shall sleep with your hand upon your weapons.’ Tricked out of his inheritance, shanghaied, shipwrecked off the west coast of Scotland, David Balfour finds himself fleeing for his life in the dangerous company of Jacobite outlaw and suspected assassin Alan Breck Stewart. Their unlikely friendship is put to the test as they dodge government troops across the Scottish Highlands. Set in the aftermath of the 1745 rebellion, Kidnapped transforms the Romantic historical novel into the modern thriller. Its heart-stopping scenes of cross-country pursuit, distilled to a pure intensity in Stevenson’s prose, have become a staple of adventure stories from John Buchan to Alfred Hitchcock and Ian Fleming. Kidnapped remains as exhilarating today as when it was first published in 1886. This new edition is based on the 1895 text, incorporating Stevenson’s last thoughts about the novel before his death. It includes Stevenson’s ‘Note to Kidnapped’, reprinted for the first time since 1922.

scholarly journals Influence of a Standing Wave Flow-Field on the Dynamics of a Spray Diffusion Flame

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski
Keyword(s):  
Liquid Phase ◽  
Flow Field ◽  
Standing Wave ◽  
Diffusion Flame ◽  
Stokes Number ◽  
Flame Height ◽  
Wave Flow ◽  
Two Dimensional ◽  
Governing Equations ◽  
First Time

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.

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