Delayed control of a Moore-Greitzer axial compressor model

Several feedback control laws have appeared in the literature concerning the stabilization of the nonlinear Moore-Greitzer axial compression model. Motivated by magnitude and rate limitations imposed by the physical implementation of the control law, Larsen et al. studied a dynamic implementation of the S-controller suggested by Sepulchre and Kokotović. They showed the potential benefit of implementing the S-controller through a first-order lag: while the location of the closed-loop equilibrium achieved with the static control law was sensitive to poorly known parameters, the dynamic implementation resulted in a small limit cycle at a very desirable location, insensitive to parameter variations. In this paper, we investigate the more general case when the control is applied with a time delay. This can be seen as an extension of the model with a first-order lag. The delay can either be a result of system constraints or be deliberately implemented to achieve better system behavior. The resulting closed-loop system is a set of parameter-dependent delay differential equations. Numerical bifurcation analysis is used to study this model and investigate whether the positive results obtained for the first-order model persist, even for larger values of the delay.

Long-term changes of Copepoda community (1957-1996) in a subtropical Chinese lake stocked densely with planktivorous filter-feeding silver and bighead carp

In contrast to the relatively well documented impact of particulate-feeding fish on zooplankton communities, little attention has been devoted to the impact of filter-feeding fish. Filter-feeding silver and bighead carp are the most intensively cultured fish species in Asia and comprise much of the production of Chinese aquaculture. However, little information is known about the impact of either fish on the zooplankton community. Long-term changes in the Copepoda community (1957-1996) were studied at two sampling stations of a subtropical Chinese lake (Lake Donghu) dominated by silver and bighead carp. For both calanoids and cyclopoids, the littoral station (I) was much more resource profitable than the pelagic station (II). There has been a tremendous increase in the annual fish catch over the past 30 years due to the increased stocking with fingerlings of the two carp species. There was a notably higher fish density at Station I than at Station II. Cyclopoid abundance was notably higher at Station I than at Station II during the 1950s to the 1980s, while the reverse became true in the 1990s. This is probably because when fish abundance increased to an extremely high level, the impact of fish predation on the cyclopoids became more important than that of food resources at the littoral station. At both stations, cyclopoid abundance was relatively low in spite of the presence of abundant prey. Similarly, calanoid density did not differ significantly between the two stations in the 1950s and 1960s, but was significantly lower at Station I than at Station II during the 1980s and 1990s. Such changes are attributed to the gradient of fish predation between the stations and an increasing predation pressure by the fish. The increased fish predation also correlated with a shift in summer-dominant calanoids from larger species to smaller ones. In conclusion, the predaceous cyclopoids are affected by fish predation to a much lesser extent than the herbivorous calanoids, and therefore increased predation by filter-feeding fish results in a definite increase in the cyclopoid/calanoid ratio. Predation by filter-feeding fish has been a driving force in shaping the copepod community structure of Lake Donghu during the past decades.

Changes of Leptodora kindti abundance (1957-1996) in a planktivorous fishes-dominated subtropical Chinese lake (Lake Donghu)

The changes of L. kindti density from 1957 to 1996 were studied in a shallow, eutrophic Chinese lake, Lake Donghu. Despite the fact that the fish yield of planktivorous fish (silver carp and bighead carp) has increased steadily, the population density of L. kindti has also increased since 1957 and peaked in 1982/1983, The increase of both fish and L. kindti densities during this period may have benefitted from a considerable increase in the densities of their zooplankton prey. and fish predation on L. kindti might have been minor. As the fish yield increased further, their predation began to suppress most zooplankton prey including L. kindti. The largely increased fish predation on L. kindti is also evidenced by the remarkable decline of their body length after 1984. The density of L. kindti was significantly higher at the pelagic station (II) than at the littoral station (I), although for L. kindti, the littoral zone was significantly more resource profitable than the pelagic zone. The gradient of fish predation (more fish in the littoral zone) is the most likely explanation, since L. kindti is reported to be a preferred prey for many planktivorous fishes. The maximum density of L. kindti was 1.78 ind./I (on Aug. 17, 1984) at Station I and 1.55 ind./I (on Sep. 13, 1985) at Station II, respectively, which are close to those in several other eutrophic lakes.

Semeadura - efeito do tratamento de sementes de soja (Glycine max (l.) Merrill) sobre a vazão do mecanismo dosador.

2004

The Failure of American and British Propaganda in the Arab Middle East, 1945-1957: Unconquerable Minds

Vaughan, J. (2005). The Failure of American and British Propaganda in the Arab Middle East, 1945-1957: Unconquerable Minds. Basingstoke: Palgrave Macmillan. RAE2008

Propaganda by Proxy?: Britain, America, and Arab Radio Broadcasting, 1953-1957

Vaughn, James, ''Propaganda by Proxy': Britain, America and Arab Radio Broadcasting 1953-1957 ', Historical Journal of Film, Radio and Television (2002) 22(2) pp.157-172 RAE2008

?A Certain Idea of Britain': British Cultural Diplomacy in the Middle East, 1945-1957?

Vaughan, J. (2005). ?A Certain Idea of Britain': British Cultural Diplomacy in the Middle East, 1945-1957. Contemporary British History. 19 (2), pp.151-168 RAE2008

The challenge of change; what is happening in home missions, by John Milton Moore.

http://www.archive.org/details/challengeofchang028207mbp

G. Ernest Wright Papers, 1957-1972

This collection primarily contains correspondence from Wright’s years as president of ASOR. Material dates as far back as 1957, and proceed into the early 1970’s. Some of Wright’s more notable correspondents include William F. Albright, A. Henry Detweiler, Paul W. Lapp, William Reed, and Dean Seiler. Subject-specific correspondence includes records of expenditures, budget planning, corporate memberships, and the Jerusalem School.

Solo and Chamber Music of Pulitzer Prize-Winning Composers

The Pulitzer Prize in Music, established in 1943, is one of America's most prestigious awards. It has been awarded to fifty-three composers for a "distinguished musical composition of significant dimension by an American that has had its first performance in the United States during the year." Composers who have won the Pulitzer Prize are considered to be at the pinnacle of their creativity and have provided the musical world with classical music compositions worthy of future notice. By tracing the history of Pulitzer Prize-winning composers and their compositions, researchers and musicians enhance their understanding of the historical evolution of American music, and its impact on American culture. Although the clarinet music of some of these composers is rarely performed today, their names will be forever linked to the Pulitzer, and because of that, their compositions will enjoy a certain sense of immortality. Of the fifty-four composers who have won the award, forty-seven have written for the clarinet in a solo or chamber music setting (five or less instruments). Just as each Pulitzer Prize-winning composition is a snapshot of the state of American music at that time, these works trace the history of American clarinet musical development, and therefore, they are valuable additions to the clarinet repertoire and worthy of performance. This dissertation project consists of two recitals featuring the solo and chamber clarinet music of sixteen Pulitzer Prize-winning composers, extended program notes containing information on each composer's life, their music, the Pulitzer Prize-winning composition and the recital selection, and a complete list of all Pulitzer Prize-winning composers and their solo and chamber clarinet music. Featured Composers Dominick Argento, To Be Sung Upon the Water Leslie Bassett, Soliloquies William Bolcom, Little Suite of Four Dances Aaron Copland, As it Fell Upon a Day John Corigliano, Soliloquy Norman Dello Joio, Concertante Morton Gould, Benny's Gig Charles Ives, Largo Douglas Moore, Quintet for Clarinet and Strings George Perle, Three Sonatas Quincy Porter, Quintet for Clarinet and Strings Mel Powell, Clarinade Shulamit Ran, Private Game Joseph Schwantner, Entropy Leo Sowerby, Sonata Ernst Toch, Adagio elegiaco

Three Voices in the Wilderness: Foote, Bloch, and Korngold in the Early Twentieth-Century America

Barbara Hanning points out in her book Concise History of Western Music, that "Twentieth-century American music was in large measure an extension of European music" (Hanning 1998, 515). My dissertation/perforrnance project features cello works written by three contemporary composers who lived in America but were connected to the European heritage in different ways; each contributed significantly to the development of American classical concert life, music education, and even popular culture. Programs of my performances are intended to illustrate their unique compositional styles. The first recital consists of five cello compositions of Massachusetts-born Arthur Foote (1853 - 1937): Drei Stucke fur Pianoforte und Violoncello, Op. 1; Scherzo, Op.22; Romanza, Op.33; Aubade, Op.77; and Sonata for Violoncello and Piano, Op.78. Foote was influenced by the German-trained John Knowles Paine at Harvard University; he composed music famous for its extensive chromaticism in both harmony and melodic line, and for clearly-defined formal structure. The second recital explores the music of Swiss-American composer Ernest Bloch (1880-1959): a short Meditation Hebraique, a Suite No. I for Violoncello Solo and the famous rhapsody Schelomo. Born in Geneva, Switzerland, and settling in the United States in 1916, Bloch is a composer deeply influenced by the European late-Romantic tradition and is also well-known for employing "Hebraic" elements into his works. The final performance comprises two other of Bloch's cello works and one cello concerto by the Austrian-American composer, Erich Wolfgang Korngold (1897- 1957). Bloch's Voice in the Wilderness is a symphonic poem for orchestra and cello (accompanied by piano in this performance), consisting of six movements performed without pause. His Suite No.3 for Cello Solo is shorter and has a simpler style than the first Suite. Korngold was recognized as a child prodigy in his native Austria. After a Nazi-induced exile, he immigrated to America and became a film music composer in Hollywood. The Cello Concerto was used in the movie "Deception" (1 946), for which Korngold provided the film score. The impassioned harmonic language and lavish melodic lines inherited from the high-romanticism make this work one of comparative discordant beauty among other compositions of his time.

CIRQUE DE LA VOIX: VOCAL PERFORMANCES FOR THE 21st CENTURY AUDIENCE

This dissertation addresses the growing need to entice people to attend a classical solo vocal recital by incorporating thematic programming, multi-media presentations, collaborations and innovative marketing. It comprises four programs that use the above tactics, creating live performances of classical vocal music that appeal to the attention deficient 21st-century audience. Each program focuses on repertoire appropriate for the male alto voice and includes elements of spoken word, visual imagery and for movement through collaborations with actors, singers, dancers, designers and visual artists. Program one (March 1, 2004), La Voix Humaine: The Life of an Englishwoman in Music, Poetry, & Art, outlines the life of a fictitious Englishwoman through a self-composed narration, spoken by an actress, a Power Point presentation of visual art by 20th-century English artists and musical commentary provided by the collaboration of a vocalist and a pianist. Program two (October 15, 2004), La Voix Thfrmatique: Anima - Music that Moves, is a program of pieces ranging from the 14th- to the 20th-centuries of which half are choreographed by members of the University of Maryland Dance Department. Program three is a lecture recital entitled L 'Haute Voix: Identifying the High Male Voice and Appropriate Repertoire which is presented in collaboration with three singers, a pianist, a harpsichordist and a cellist. Program four, La Voix Dramatique: Opera Roles for the Countertenor Voice, comprises performances of George Frederic Handel's Giulio Cesare in Egitto (1724) in collaboration with the Maryland Opera Studio and the Clarice Smith Performing Arts Center (Leon Major, director; Kenneth Merrill, conductor). There are two performances each of the title role, Cesare (April 15 & 17, 2005), and his nemesis, Tolomeo (April 21 & 23,2005). All programs are documented in a digital audio format available on compact disc and are accompanied by program notes also available in digital format. Programs two and four are also documented in digital video format available on digital video disc.

BLAZE: Bettering the lives of animals in zoo environments

Gemstone Team BLAZE