1,511 research outputs found
Noise due to unsteady flow past trailing edges
No full textThis paper presents two-dimensional direct numerical simulations (DNS) of noise generated at trailing edges (TE) with zero thickness. The simulations are conducted specifying either no-slip or slip walls in order to investigate viscous effects. In both cases, small amplitude disturbances are introduced close to the inflow boundary that serve as pressure disturbances at the TE. DNS data reveals that the unsteady Kutta condition is not satisfied, irrespective of the wall boundary condition. However, it appears that the validity of the unsteady Kutta condition is not essential for making an accurate prediction of the far field noise. The far field pressure is predicted as a function of the surface pressure difference using a 2-D modification of Amiet's classical theory, and compared with the far field pressure computed directly. Directivity plots provide evidence that the presence of boundary layers and noise generated by an unsteady wake in the no-slip cases lead to smearing of individual lobes, and that the downstream pointing lobes in no-slip wall cases are probably due to nonlinear noise generation in the wake. The simulations are conducted using a high-order accurate numerical method which is free of upwinding, artificial dissipation or any form of explicit filtering, and employs a novel boundary treatment
Music for classical guitar by South African composers : a historical survey, notes on selected works and a general catalogue
No full textIncludes abstract.Includes bibliographical references (leaves 296-309).This is the first comprehensive investigation of music for, or including, the classical guitar by South African composers. The focus of this research has been, firstly, to uncover as much of the repertoire as possible, and, secondly, to collate, study, catalogue and report on the information. A brief historical survey of the guitar in South Africa provides the context within which this study was conducted. The primary sources of quantitative data collection were through the archival catalogues of the South African Music Rights Organisation and through personal contact with guitarists, composers and guitar teachers. Other sources consulted were publishers, broadcasting corporations, recording companies, libraries and the internet. The body of the dissertation comprises biographical sketches, background notes, analyses and technical notes on 17 selected solo and chamber works dating from 1947 to 2007 by some of South Africa's most prominent composers and guitaristcomposers. The repertoire ranges in style from the traditional and ethnically inspired to the experimental and abstract. As this is an empirical survey, each selected entry includes details on instrumentation, duration, level of difficulty, number of pages, scordatura, commissions or requests, sources or publishers, premières and recordings. A biography of each composer is provided as well as background notes which offer an overview of the selected work. The notes discuss historical, cultural, musical and extra-musical influences, and frequently include references to interview material. The commentaries on the selected works, with musical examples, include an analytical component describing structure, form, stylistic and compositional elements, while the technical observations include performance suggestions and a grading for each work
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
Jews and gender in British literature 1815-1865.
No full textPhDThis thesis examines the variety of relationships between Jews and gender in early
to mid-nineteenth century British literature, focussing particularly on representations
of and by Jewish women. It reconstructs the social, political and literary context in
which writers produced images and narratives about Jews, and considers to what
extent stereotypes were reproduced, appropriated, or challenged. In particular it
examines the ways in which questions of gender were linked to ideas about religious
or racial difference in the Victorian period.
The study situates literary representations of Jews within the context of
contemporary debates about the participation of the Jews in the life of the modern
state. It also investigates the ways in which these political debates were gendered,
looking in particular at the relationship between the cultural construction of
femininity and English national identity.
It first considers Victorian culture's obsession with Rebecca, the Jewess created in
Walter Scott's influential novel Ivanhoe (1819). It examines Rebecca's refusal to
convert to Christianity in the context of Scott's discussion of racial separatism and
modern national unity.
Evangelical writers like Annie Webb, Amelia Bristow and Mrs Brendlah were
prolific literary producers, and preoccupied with converting Jewish women.
Particularly during the 18'40s and 1850s, evangelical writing provided an important
forum for the construction and consolidation of women's national identity.
Grace Aguilar's writing was an attempt to understand Jewish identity within the
terms of Victorian domestic ideology. In contrast, Celia and Marion Moss, in their
historical romances, offered narratives of female heroism and national liberation,
drawing on the contemporary debate about slavery.
Benjamin Disraeli's construction of a "tough version of Jewish identity was a
response both to the contemporary stereotype of the feminised Jew and to the debate
about Jewish emancipation. It also drew on the virile ideology of the Young England
movement of the 1840s
Narrative support for technical documents: Formalising Rhetorical Structure Theory
No full textBusiness Process Re-engineering (BPR) is an area that requires a lot of technical documents and an important feature of a well-written document is a coherent narrative. Even though computer software has helped authors in many other aspects of writing, support for document narratives is almost non-existent. Therefore, we introduce CANS (Computer-Aided Narrative Support), a tool that uses Rhetorical Structure Theory to enhance the narrative of a document. From this narrative, the tool generates questions to prompt the author for the content of the document. CANS also allows the author to explore alternative narratives for a document. A catalogue of predefined narrative structures for popular types of documents is provided too. Our tool is still in its rudimentary stages but sufficiently complete to be demonstrated
Turbulent heat transfer in channels with irregular roughness
No full textIt is well known that rough surfaces affect turbulent flows significantly. How such surfaces affect turbulent heat transfer is less well understood. To gain more insight, we have performed a series of direct numerical simulations of turbulent heat transfer in a channel flow with grit-blasted surfaces. An immersed boundary method is used to account for the rough surface. A source term in the thermal energy balance is used to maximise the analogy between the transport of heat and the transport of streamwise momentum. The wall roughness size is varied from to =120. Turbulence statistics like mean temperature profile, mean temperature fluctuations and heat fluxes are presented. The structure of the turbulent temperature field is analysed in detail. Recirculation zones, which are the result of an adverse pressure gradient, have a profound effect on heat transfer. This is important as it leads to the wall-scaled mean temperature profiles being of larger magnitude than the mean velocity profiles both inside and outside the roughness layer. This means that the temperature wall roughness function is different from the momentum wall roughness function . Since the bulk temperature and velocity depend on and , it was shown that the Stanton number and the skin friction factor directly depend on and , respectively. Therefore, the failure of the Reynolds analogy in fully rough conditions can be directly related to the difference between and
Increasing science, technology, engineering, and mathematics skills using Project Lead the Way
No full textIncludes bibliographical references
Paralegal work: a community-based approach to fisheries law enforcement ni Negros Occidental, Philippines
No full textFishery management, Legal aspects
Reid, Forrest, [1904] [n.m.] [n.d.]
No full text"copy of published letter from Jobe, August 2000; transcription only; "I am obliged to you"; redated from [n.y.] 7/30/10 RDS"Unknow
In Shadow of Great Brother: Diplomat and Financier N.D. Kiselyov
No full textThe author analyzes famous Russian diplomat N.D. Kiselyov's participation in the financial transactions on purchase and sale of French rent in the middle of the 19th century. It is a rare example of Russia crediting of an industrially developed Western European country. It should be noted that all archival documents both in French and Russian used in the article are published for the first time
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