972 resultados para chamber


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A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its photooxidation products, phthaldialdehyde and 1-nitronaphthalene. The measured yields of secondary organic aerosol (SOA) arising from the photooxidation of naphthalene varied from 6-20%, depending on the concentrations of naphthalene and nitrogen oxides as well as relative humidity. A range of carbonyls, nitro-compounds, phenols and carboxylic acids were identified among the gas- and particle-phase products. On-line analysis of the chemical composition of naphthalene SOA was performed using aerosol time-of-flight mass spectrometry (ATOFMS) for the first time. The results indicate that enhanced formation of carboxylic acids may contribute to the observed increase in SOA yields at higher relative humidity. The photolysis of phthaldialdehyde and 1-nitronaphthalene was investigated using natural light at the European Photoreactor (EUPHORE) in Valencia, Spain. The photolysis rate coefficients were measured directly and used to confirm that photolysis is the major atmospheric loss process for these compounds. For phthaldialdehyde, the main gas-phase products were phthalide and phthalic anhydride. SOA yields in the range 2-11% were observed, with phthalic acid and dihydroxyphthalic acid identified among the particle phase products. The photolysis of 1-nitronaphthalene yielded nitric oxide and a naphthoxy radical which reacted to form several products. SOA yields in the range 57-71% were observed, with 1,4-naphthoquinone, 1-naphthol and 1,4-naphthalenediol identified in the particle phase. On-line analysis of the SOA generated in an indoor chamber using ATOFMS provided evidence for the formation of high-molecular-weight products. Further investigations revealed that these products are oxygenated polycyclic compounds most likely produced from the dimerization of naphthoxy radicals. These results of this work indicate that naphthalene is a potentially large source of SOA in urban areas and should be included in atmospheric models. The kinetic and mechanistic information could be combined with existing literature data to produce an overall degradation mechanism for naphthalene suitable for inclusion in photochemical models that are used to predict the effect of emissions on air quality.

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Mercury is a potent neurotoxin even at low concentrations. The unoxidised metal has a high vapour pressure and can circulate through the atmosphere, but when oxidised can deposit and be accumulated through the food chain. This work aims to investigate the oxidation processes of atmospheric Hg0(g). The first part describes efforts to make a portable Hg sensor based on Cavity Enhanced Absorption Spectroscopy (CEAS). The detection limit achieved was 66 ngm−3 for a 10 second averaging time. The second part of this work describes experiments carried out in a temperature controlled atmospheric simulation chamber in the Desert Research Institute, Reno, Nevada, USA. The chamber was built around an existing Hg CRDS system that could measure Hg concentrations in the chamber of<100 ngm−3 at 1 Hz enabling reactions to be followed. The main oxidant studied was bromine, which was quantified with a LED based CEAS system across the chamber. Hg oxidation in the chamber was found to be mostly too slow for current models to explain. A seven reaction model was developed and tested to find which parameters were capable of explaining the deviation. The model was overdetermined and no unique solution could be found. The most likely possibility was that the first oxidation step Hg + Br →HgBr was slower than the preferred literature value by a factor of two. However, if the more uncertain data at low [Br2] was included then the only parameter that could explain the experiments was a fast, temperature independent dissociation of HgBr some hundreds of times faster than predicted thermolysis or photolysis rates. Overall this work concluded that to quantitatively understand the reaction of Hg with Br2, the intermediates HgBr and Br must be measured. This conclusion will help to guide the planning of future studies of atmospheric Hg chemistry.

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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

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Throughout his long and industrious lifetime, Camille Saint-Saens (1835-1921) devoted himself unconditionally to music both as a composer and a performer. Saint-Saens was a self-described traditionalist and musical purist, yet his works are distinctly expressive and imaginative, and they reflect the composer's own unique musical language which incorporates recognizably modem traits such as chromaticism and frequent modulation. As a performer, Saint-Saens preferred to premiere his own works and often included his chamber music in his concert programs. Regarded primarily as a symphonic composer in the present day, however, his extensive and varied collection of chamber music works is sadly neglected. Six varied small-ensemble works with piano from his chamber music repertoire have been selected for study and recording for this project: Piano Trio No. 1 in F Major, Op. 18 (1864); Sonata for Cello and Piano No. 1 inC Minor, Op. 32 (1872); two pieces for two pianos, Le Rouet d'Omphale (The Spinning Wheel ofOmphale), Op. 31 (1871) and Phaeton, Op. 39 (1874); piano duet Konig Harald Haifagar (King Harald Haarfager), Op. 59 (1880); and a wind quartet, Caprice sur des airs Danois et Russes (Caprice on Danish and Russian Airs) for Flute, Oboe, Clarinet and Piano, Op. 79 (1887). Analyses of the forms and harmonic structures of these compositions will be included in this dissertation paper as well as studies from the viewpoint of Saint-Saens' compositional style, ensemble characteristics, and writing for the piano. The recordings for this project were made in four sessions in LeFrak Concert Hall at Queens College, the City University of New York. On September 24, 2003, Op. 31, Op. 39 and Op. 59 were recorded with Professor Morey Ritt, piano. On March 2, 2004, Op. 18 was recorded with Elena Rojas, violin, and Clare Liu, cello, and on March 15, 2004, Op. 32 was recorded, also with Ms. Liu. The Caprice, Op. 79 was recorded on June 27, 2008 with Laura Conwesser, flute; Randall Wolfgang, oboe; and Steve Hartman, clarinet. The recordings may be found on file in the library at the University of Maryland, College Park.

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The trumpet experienced important changes in terms of its musical use during the middle and late Baroque period. Prior to the Baroque, and even in to the first half of the 17th century, the trumpet had historically been used for rather "non-musical" purposes, sometimes as an instrument for battle or as a tool to be used in the town square to announce the arrival of a dignitary. On the whole, the trumpet was most certainly not used as an instrument of melody -that was typically reserved for violins, flutes, and oboes. However, in the late 1600's, composers such as Allesandro Stradella and Henry Purcell began to treat the trumpet differently. They saw the melodic potential in the trumpet and began to feature the trumpet more as an instrument of melody, as opposed to relegating it to only outlining triads and emphasizing harmony. Of course, keyboard, string, and woodwind instruments had long established a significant catalogue of works by the late 17th century. Additionally, even after the trumpet had been established as an instrument of melody, prominent composers of the time still wrote significantly more solo music for these other instrument families than for the trumpet. Consequently, the overall Baroque repertoire for the solo trumpet pales in comparison to that of the other families of instruments. But, much of this Baroque literature not originally written for trumpet can be presented effectively in the form of a transcription, thereby adding greatly to the repertoire of the Baroque solo trumpet. The goal of these three dissertation recitals is twofold: 1) to perform literature that offers music from a variety of countries of origin that span the entire Baroque era and 2) to feature music that has remained relatively unknown in the trumpet world, yet is musically strong. I will also introduce viable "new" music to the trumpet repertoire through Baroque transcriptions originally written for other instruments or voice. The majority of the transcriptions I will be performing have originated from my own listening and study of Baroque music, and I have selected music that I felt would translate well for the trumpet.

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During the period of 1990-2005, American-born women composers have contributed significantly to the standard clarinet repertoire. Pioneering composers such as Joan Tower, Margaret Brouwer, and Libby Larsen have created staples for clarinet literature. Yet, there is very little scholarly research on women composers of clarinet music, most being concentrated on Joan Tower. Through my research, I have discovered over seventy-five works by more than fifty composers in the following genres: solo clarinet; clarinet and piano; clarinet and voice, with or without piano; and small chamber pieces for up to five players. This performance dissertation project consists of three recitals featuring solo and chamber works by nine living women composers, and program notes containing pertinent biographical and compositional information. My intent is to increase recognition women composers, both prominent and lesser known, who are writing high-quality, accessible clarinet literature. Each woman selected is making a full or partial living from the sales of her compositions, has received recognition through awards, commissions, grants, and frequent performances, and has composed works that are both performer and audience accessible. Recital 1: Trios for Clarinet, Violin, and Piano Commissioned by the Verdehr Trio and Composed by American-Born Women Composers. Composers: Jennifer Higdon, Joan Tower, Margaret Brouwer, and Libby Larsen. Recital II: Programmatic Clarinet Works by American-Born Women Composers. Composers: Andrea Clearfield, Stella Sung, and Karen Amrhein. Recital III: Works for Solo Clarinet, Clarinet and Piano, and Clarinet Concerto Genres by American-Born Women Composers. Composers: Persis Parshall Vehar, Jenni Brandon, Margaret Brouwer, and Libby Larsen.

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Understanding tumor vascular dynamics through parameters such as blood flow and oxygenation can yield insight into tumor biology and therapeutic response. Hyperspectral microscopy enables optical detection of hemoglobin saturation or blood velocity by either acquiring multiple images that are spectrally distinct or by rapid acquisition at a single wavelength over time. However, the serial acquisition of spectral images over time prevents the ability to monitor rapid changes in vascular dynamics and cannot monitor concurrent changes in oxygenation and flow rate. Here, we introduce snap shot-multispectral imaging (SS-MSI) for use in imaging the microvasculature in mouse dorsal-window chambers. By spatially multiplexing spectral information into a single-image capture, simultaneous acquisition of dynamic hemoglobin saturation and blood flow over time is achieved down to the capillary level and provides an improved optical tool for monitoring rapid in vivo vascular dynamics.

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French chamber music in the last quarter of the nineteenth century displayed significant advances in musical innovations and technical developments. As the Parisian public began to favor instrumental music and mélodie over opera, vocal and chamber music with piano became one of the main genres to express French composers’ creativity and individuality. The composers Franck, Debussy, Fauré, Duparc, Ravel, Chausson and Poulenc were the major contributors to this unusually creative period in French music. French mélodies of this period blend precision with lyricism, and demand the performer’s elegance and wit. They show careful settings of the French language’s rhythmic subtleties and increased expressiveness in and importance of the piano accompaniment. The chamber works of this period demanded superior pianistic and instrumental virtuosity while displaying wide ranges of sonority, multiple tone colors, and rhythmic fluidity. The three recitals which comprise this dissertation project were performed at the University of Maryland Gildenhorn Recital Hall on 27 October 2006, All Nations Mission Church (Dayton, NJ) on 5 December 2009, and the Leah M. Smith Lecture Hall of the University of Maryland on 11 May 2010. The repertoire included Poulenc’s Sonata for Oboe and Piano (1962) with oboist Yeongsu Kim, French mélodies by Fauré, Chausson, Debussy, Ravel and Duparc with soprano Jung-A Lee and baritone Hyun-Oh Shin, Poulenc’s Sextet for Piano, Flute, Oboe, Clarinet, Bassoon and Horn (1932-1939) with flutist Katrina Smith, clarinetist Jihoon Chang, bassoonist Erich Heckscher, hornist Heidi Littman and oboist Yeongsu Kim, Debussy’s Sonata for Cello and Piano (1915) with cellist Ji-Sook Shin, Poulenc’s Sonata for Violin and Piano (1942-1949) with violinist Ji-Hee Lim, Franck’s Sonata for Violin and Piano (1886) with violinist Na-Young Cho, Ravel’s Piano Trio (1915) with cellist Ji-Sook Shin and violinist Yu-Jeong Lee and Ravel’s Sonata for Violin and Piano (1927) with violinist Yu-Jeong Lee. The recitals were recorded on compact discs and are archived within the Digital Repository at the University of Maryland (DRUM).

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This dissertation project explores some of the technical and musical challenges that face pianists in a collaborative role—specifically, those challenges that may be considered virtuosic in nature. The material was chosen from the works of Rachmaninoff and Ravel because of the technically and musically demanding yet idiomatic piano writing. This virtuosic piano writing also extends into the collaborative repertoire. The pieces were also chosen to demonstrate these virtuosic elements in a wide variety of settings. Solo piano pieces were chosen to provide a point of departure, and the programmed works ranged from vocal to two-piano, to sonatas and a piano trio. The recitals were arranged to demonstrate as much contrast as possible, while being grouped by composer. The first recital was performed on April 24, 2009. This recital featured five songs of Rachmaninoff, as well as three solo piano preludes and his Suite No. 2 for two pianos. The second recital occurred on November 16, 2010. This recital featured the music of both Rachmaninoff and Ravel, as well as a short lecture introducing the solo work “Ondine” from Gaspard de la nuit by Ravel. Following the lecture were the Cinq mélodies populaires grecques and the program closed with the substantial Rachmaninoff Sonata for Cello and Piano. The final program was given on October 10, 2011. This recital featured the music of Ravel, and it included his Sonata for Violin and Piano, the Debussy Nocturnes transcribed for two pianos by Ravel, and the Piano Trio. The inclusion of a transcription of a work by another composer highlights Ravel’s particular style of writing for the piano. All of these recitals were performed at the Gildenhorn Recital Hall in the Clarice Smith Performing Arts Center at the University of Maryland. The recitals are recorded on compact discs, which can be found in the Digital Repository at the University of Maryland (DRUM).

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Chamber music repertoire featuring the piano blossomed from the mid-nineteenth through the early twentieth century. The quantity of works increased greatly during this time and the quality of these works reached the highest level. Among the many symbolic works that were composed were sonatas for a single string instrument with piano, piano trios, quartets: and quintets as well as two-piano works and four-hand duets. Being able to study and perform many of these iconic works before I graduated was one of the major goals I set for myself as a collaborative pianist. The abundance of repertoire has made it easy to choose works considered "iconic" for my dissertation's three recitals. Iconic is defined as "very famous or popular, especially being considered to represent particular opinions or a particular time" in the online Cambridge Advanced Leamer's Dictionary & Thesaurus © Cambridge University. The compositions featured in the recitals were composed from 1842 through 1941, including works by Schumann, Brahms, Faure, Rachmaninoff, Ravel, and Lutoslawski. Choosing the repertoire with my fellow performers in mind was an important part of this dissertation. In addition to trying to make balanced programs which include variety, working with different instruments and performers is one of the most fulfilling parts of the musical experience for me as a collaborative pianist. Joining me for the concerts were members of the Aeolus String Quartet (violinist Nicholas Tavani, violinist Rachel Shapiro, violist Greg Luce, and cellist Alan Richardson), pianist Hsiao-Ying Lin (a doctoral student from the Peabody Conservatory), and my colleagues from the Peabody Institute Preparatory Division (faculty violinist Dr. Christian Tremblay and cellist Alicia Ward), and Derek Smith, Associate Principal violist of the Annapolis Symphony Orchestras). The three recitals were performed in the Gildenhom and Ulrich Recital Halls at the University of Maryland, College Park, Maryland. They are recorded on CD and available on compact discs, which can be found in the Digital Repository at the University of Maryland (DRUM).

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The musical period of Neoclassicism began in the 1920's, between the first and second world wars. It was initiated by French composers and eventually spread to other countries. One of the most important themes to emerge from the movement was to escape from the formless, rather emotional music of the Romantic era and instead, emphasize balance, order, objectivity and clarity in musical form. Many popular clarinet repertoires are enjoyed by performers and listeners because the music is enjoyable to play and easy to listen to. In particular, classically influenced clarinet music is quite interesting because it features musical elements from both the past and contemporary musical styles. For instance, some composers have integrated preexisting, more traditional styles of composition with lighter styles of modern culture such as popular music and Jazz. It is difficult to discover purely neoclassical clarinet repertoires even though many composers created their pieces during the neoclassical era. What we most commonly find are both neoclassical and non-neoclassical influences in compositions from that time period. Thus, I aim to trace the influence of neoclassicism in selected clarinet repertoires that exist today. It is my hope that increased awareness and knowledge about accessible clarinet music may encourage the general public to develop a deeper interest in a wider sphere of clarinet music, beyond what is considered popular today. The works performed and discussed in this dissertation are the following: (Recital I) Duo Concertante by Darius Milhaud; Sonata by Leonard Bernstein; Sonata for Two Clarinets by Francis Poulenc; Duos for Flute and Clarinet, Op. 34 by Robert Muczynski; Dance Preludes by Witold Lutoslawski, (Recital II) Sonatine by Arthur Honegger; Time pieces by Robert Muczynski; Suite for Clarinet, Violin and Piano by Darius Milhaud; Sonate for Clarinet, Flute and Piano by Maurice Emmanuel; Tarantelle for Flute, Clarinet and Piano, Op. 6 by Camille Saint-Saëns, (Recital III) Sonatina by Joseph Horovitz; Suite from L'histoire du Soldat for Clarinet, Violin and Piano by Igor Stravinsky; Contrasts for Clarinet, Violin and Piano by Béla Bartók The recitals that took place on December 1, 2012 and on April 25, 2013 were performed in the Ulrich Recital Hall of the Clarice Performing Arts Center in College Park, Maryland. The recital that took place on November 2, 2013 was performed at the Gildenhorn Recital Hall of the same performing arts center.

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The radiation efficiency and resonance frequency of five compact antennas worn by nine individual test subjects was measured at 2.45 GHz in a reverberation chamber. The results show that, despite significant differences in body mass, wearable antenna radiation efficiency had a standard deviation less than 0.6 dB and the resonance frequency shift was less than 1% between test subjects. Variability in the radiation efficiency and resonance frequency shift between antennas was largely dependant on body tissue coupling which is related to both antenna geometry and radiation characteristics. The reverberation chamber measurements were validated using a synthetic tissue phantom and compared with results obtained in a spherical near field chamber and finite-difference time-domain (FDTD) simulation.