908 resultados para Output performances


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This study aimed at evaluating the ploidy effects on growth performances of Chinese shrimp (Fenneropenaeus chinensis Osbeck, 1765) reared in different salinities under laboratory conditions. In the acute salinity experiment, there was no difference (P > 0.05) in tolerance observed in triploid and diploid shrimp due to abrupt salinity changes. The lethal salinity for 50% of the individuals in 96 h at 23-25 degrees C was about 2 g L-1 in both triploids and diploids. While for the chronic salinity experiment, statistical analyses confirmed that the differences in growth performances including the specific growth rate (SGR), the feeding rate (FR), feed conversion efficiency (FCE) and intermoult period (IP) between triploid and diploid were related to salinity. Diploid shrimp reared in 20 g L-1 exhibited highest SGR (P < 0.05), while triploids performed well in 20 and 30 g L-1 salinities (P < 0.05). Based on the survival and growth data, the optimal salinity for the culture of diploid F. chinensis should be 20 g L-1 and for triploids it should be between 20 and 30 g L-1.

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In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the surface and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxygraph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and bottom thalli, respectively. The results showed that the maximal PSII quantum yield of the floating thalli was significantly lower than the normal level although their photosynthetic activities were relatively high; the photosynthetic potential of the thalli form the mud surface was extremely low. Thus, it is indicated that the floating thalli are seriously stressed by their environment and the thalli from the mud surface are already dead or are dying. On the other hand, the results of the laboratory cultivation showed that the sedimentary thalli cannot regain normal photosynthetic activity even under normal illumination conditions. Thus, the thalli from the mud surface cannot become reproductive source of the alga even if they can reach sea surface again. Therefore, a preliminary conclusion can be reached that, up to mid-July 2008, the environmental conditions of the Qingdao sea area are not suitable for the growth of the alga E. prolifera and for this reason the biomass of E. prolifera, in the area, could be declining.

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The shell-side flow distribution of a parallel flow hollow-fiber gas permeator was characterized using a thermo-anemograph. The permeator has an internal diameter of 103 mm and contains 21000 fibers. The overall fiber packing fraction is 40.1%. Experimental results revealed that shell-side flow maldistributions exist in the operating conditions studied. The gas-flow velocity is the highest at the permeator center, but lowest near the shell wall. The effects of shell-side flow maldistribution on predicted permeator performances are discussed with a simple model. Model calculation results show that flow maldistributions can have considerable effect on permeation systems with relatively high separation factors and stage cuts. (C) 1998 Elsevier Science B.V.

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Surface structures of Pt-Sn and Pt-Fe bimetallic catalysts have been investigated by means of Mossbauer spectroscopy, Pt-L-III -edge EXAFS and H-2-adsorption. The results showed that the second component, such as Sn or Fe, remained in the oxidative state and dispersed on the gamma-Al2O3 surface after reduction, while Pt was completely reduced to the metallic state and dispersed on either the metal oxide surface or the gamma-Al2O3 surface. By correlating the distribution of Pt species on different surfaces with the reaction and adsorption performances, it is proposed that two kinds of active Pt species existed on the surfaces of both catalysts, named M-1 sites and M-2 sites. M-1 sites are the sites in which Pr directly anchored on the gamma-Al2O3 surface, while M-2 sites are those in which Pt anchored on the metal oxide surface. M-1 sites are favorable for low temperature H-2 adsorption, and responsible for the hydrogenolysis reaction and carbon deposition, while M-2 sites which adsorb more H-2 at higher temperature, are more resistant to the deactivation due to less carbon deposition, and provide major contribution to the dehydrogenation reaction.

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The silver catalyzed, selective catalytic reduction (SCR) of nitrogen oxides (NOx) by CH4, is shown to be a structure-sensitive reaction. Pretreatment has a great affect on the catalytic performances. Upon thermal treatment in inert gas stream, thermal induced changes in silver morphology lead to the formation of reduced silver species of clusters and particles. Catalysis over this catalyst indicates an initially higher activity but lower selectivity for the CH4-SCR of NOx Reaction induced restructuring of silver results in the formation of ill-defined silver oxides. This, in turn, impacts the adsorption properties and diffusivity of oxygen over silver catalyst, results in the decrease in activity but increase in selectivity of Ag-H-ZSM-5 catalyst for the CH4-SCR of NO.. (c) 2004 Elsevier B.V. All rights reserved.

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In 1966, Roy Geary, Director of the ESRI, noted “the absence of any kind of import and export statistics for regions is a grave lacuna” and further noted that if regional analyses were to be developed then regional Input-Output Tables must be put on the “regular statistical assembly line”. Forty-five years later, the lacuna lamented by Geary still exists and remains the most significant challenge to the construction of regional Input-Output Tables in Ireland. The continued paucity of sufficient regional data to compile effective regional Supply and Use and Input-Output Tables has retarded the capacity to construct sound regional economic models and provide a robust evidence base with which to formulate and assess regional policy. This study makes a first step towards addressing this gap by presenting the first set of fully integrated, symmetric, Supply and Use and domestic Input-Output Tables compiled for the NUTS 2 regions in Ireland: The Border, Midland and Western region and the Southern & Eastern region. These tables are general purpose in nature and are consistent fully with the official national Supply & Use and Input-Output Tables, and the regional accounts. The tables are constructed using a survey-based or bottom-up approach rather than employing modelling techniques, yielding more robust and credible tables. These tables are used to present a descriptive statistical analysis of the two administrative NUTS 2 regions in Ireland, drawing particular attention to the underlying structural differences of regional trade balances and composition of Gross Value Added in those regions. By deriving regional employment multipliers, Domestic Demand Employment matrices are constructed to quantify and illustrate the supply chain impact on employment. In the final part of the study, the predictive capability of the Input-Output framework is tested over two time periods. For both periods, the static Leontief production function assumptions are relaxed to allow for labour productivity. Comparative results from this experiment are presented.

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The potential of the violoncello as a solo instrument was recognized and supported by cellists such as Luigi Boccherini (1743-1805), Luis Duport (1749-1819), Auguste Franchomme (1808-1884), and Alfredo Piatti (1822-1901). These pioneers composed technically demanding etudes, exercises, and caprices for the cello that were comparable to those already present in the violin literature. Even so, in the late nineteenth century and early twentieth century, considerably fewer substantial works were brought forth for the cello as compared with the violin. Consequently, many cellists such as Luigi Silva (1903-1961), Gregor Piatigorsky (1903-1976), Pierre Fournier (1906-1986), and Janos Starker (b. 1924) selected notable pieces from the violin repertoire and transcribed these for the cello. Some composers themselves actually adapted for the cello their own works originally written for the violin. Johannes Brahms with his Violin Sonata Op. 78, Igor Stravinsky with his Suite Italienne, and Béla Bartók with his First Rhapsody all belong to this category. Adaptations such as these further raised awareness among composers and performers of the possibilities of the cello as an independent and expressive instrument. Thus, many composers from the early 1900s to the present were encouraged to write increasing numbers of more soloistic and demanding works for cello. Herein, I explore the repertoire of cello transcriptions in order to analyze the differences between the original and transcribed versions and the challenges found therein. The performer may attempt to recreate the effect originally intended for the violin or, more daringly, may strive to search for alternate presentations of the music more suitable and expressive of the cello's own character. The project includes two recitals of the following transcribed works presented at the University of Maryland College Park, School of Music: Sonata in A by César Franck, transcribed by Jules Delsart, Variations on a Theme from Rossini by Nicolo Paganini, transcribed by Fournier, Suite Italienne by Igor Stravinsky, transcribed with the help of Piatigorsky, Sonatina Op. 137, No. 1 by Franz Schubert, transcribed by Starker, First Rhapsody by Béla Bartók and Sonata, Op. 108 by Johannes Brahms, transcribed by Hsiao-mei Sun.

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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.

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Paul Hindemith has made numerous contributions to the viola, both as a composer and performer. As a composer, he has written 7 sonatas for the viola, as well as a number of chamber and orchestral works which feature the viola as a solo instrument. As a violist, Hindemith was one of the only virtuoso soloists of his lifetime, and premiered virtually all of his solo compositions. Many of his pieces remain an integral part of the viola repertoire; Der Schwanendreher is one of the three major Twentieth-Century concertos for the viola. While some of his pieces are well-known, there are many others which are not performed with much frequency, due in part to the sheer output of this prolific composer. In this dissertation project, I performed Hindemith's compositions for the viola as a solo instrument. Consideration was given to exclusively performing his 4 solo sonatas and 3 sonatas for viola and piano. His only viola duet, his only non-sonata written for viola and piano, and 2 of his viola concertos (Der Schwanendreher and Trauermusik) were included in this dissertation project to provide contrast and supplement the three recital programs. Through this dissertation project I have been able to gain a deeper understanding of the complex language of Hindemith and interpret his music in an approach that is accessible to both the performer and the audience. All performances took place in the Gildenhom Recital Hall and Ulrich Recital Hall at the University of Maryland. All collaborations with piano were performed with Eliza Ching. The Duett for Viola and Violoncello was performed with Daniel Shomper, and the assisting musicians performing in the Trauermusik were Joel Ciaccio, Daniel Sender, Daniel Shomper, Cassandra Stephenson and Dana Weiderhold.

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The NOMAD spectrometer suite on the ExoMars Trace Gas Orbiter will map the composition and distribution of Mars atmospheric trace species in unprecedented detail, fulfilling many of the scientific objectives of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument is a combination of three channels, covering a spectral range from the UV to the IR, and can perform solar occultation, nadir and limb observations. In this paper, we present the science objectives of the instrument and how these objectives have influenced the design of the channels. We also discuss the expected performance of the instrument in terms of coverage and detection sensitivity.

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The aim of this study was to examine the effects of cadence and power output on physiological and biomechanical responses to incremental arm-crank ergometry (ACE). Ten male subjects (mean +/- SD age, 30.4 +/-5.4 y; height, 1.78 +/-0.07 m; mass, 86.1 +/-14.2 kg) undertook 3 incremental ACE protocols to determine peak oxygen uptake (VO2 peak; mean of 3 tests: 3.07 +/- 0.17 L.min-1) at randomly assigned cadences of 50, 70, or 90 r.min-1. Heart rate and expired air were continually monitored. Central (RPE-C) and local (RPE-L) ratings of perceived exertion were recorded at volitional exhaustion. Joint angles and trunk rotation were analysed during each exercise stage. During submaximal power outputs of 50, 70, and 90 W, oxygen consumption (VO2) was lowest for 50 r.min-1 and highest for 90 r.min-1 (p < 0.01). VO2 peak was lowest during 50 r.min-1 (2.79 +/-0.45 L.min-1; p < 0.05) when compared with both 70 r.min-1 and 90 r.min-1 (3.16 +/-0.58, 3.24 +/-0.49 L.min-1, respectively; p > 0.05). The difference between RPE-L and RPE-C at volitional exhaustion was greatest during 50 r.min-1 (2.9 +/- 1.6) when compared with 90 r.min-1 (0.9 +/- 1.9, p < 0.05). At VO2 peak, shoulder range of motion (ROM) and trunk rotation were greater for 50 and 70 r.min-1 when compared with 90 r.min-1 (p < 0.05). During submaximal power outputs, shoulder angle and trunk rotation were greatest at 50 r.min-1 when compared with 90 r.min-1 (p < 0.05). VO2 was inversely related to both trunk rotation and shoulder ROM during submaximal power outputs. The results of this study suggest that the greater forces required at lower cadences to produce a given power output resulted in greater joint angles and range of shoulder and trunk movement. Greater isometric contractions for torso stabilization and increased cost of breathing possibly from respiratory-locomotor coupling may have contributed increased oxygen consumption at higher cadences.