Hydrogen adsorption on functionalized nanoporous activated carbons

There is considerable interest in hydrogen adsorption on carbon nanotubes and porous carbons as a method of storage for transport and related energy applications. This investigation has involved a systematic investigation of the role of functional groups and porous structure characteristics in determining the hydrogen adsorption characteristics of porous carbons. Suites of carbons were prepared with a wide range of nitrogen and oxygen contents and types of functional groups to investigate their effect on hydrogen adsorption. The porous structures of the carbons were characterized by nitrogen (77 K) and carbon dioxide (273 K) adsorption methods. Hydrogen adsorption isotherms were studied at 77 K and pressure up to 100 kPa. All the isotherms were Type I in the IUPAC classification scheme. Hydrogen isobars indicated that the adsorption of hydrogen is very temperature dependent with little or no hydrogen adsorption above 195 K. The isosteric enthalpies of adsorption at zero surface coverage were obtained using a virial equation, while the values at various surface coverages were obtained from the van't Hoff isochore. The values were in the range 3.9-5.2 kJ mol(-1) for the carbons studied. The thermodynamics of the adsorption process are discussed in relation to temperature limitations for hydrogen storage applications. The maximum amounts of hydrogen adsorbed correlated with the micropore volume obtained from extrapolation of the Dubinin-Radushkevich equation for carbon dioxide adsorption. Functional groups have a small detrimental effect on hydrogen adsorption, and this is related to decreased adsorbate-adsorbent and increased adsorbate-adsorbate interactions.

Reactions of nitrogen and oxygen surface groups in nanoporous carbons under inert and reducing atmospheres

The reactions of surface functional groups have an important role in controlling conversion of char nitrogen to NOx during coal combustion. This study involved an investigation of the thermal stability and reactions of nitrogen surface functional groups in nanoporous carbons. Four suites of carbons, which were used as models for coal chars, were prepared with a wide range of nitrogen and oxygen contents and types of functional groups. The porous structures of the carbons were characterized by gas adsorption methods while chemical analysis, X-ray photoelectron spectroscopy, and X-ray near edge structure spectroscopy were used to characterize the surface functional groups. Temperature programmed desorption and temperature programmed reduction methods were used to study the reactivity of the surface functional groups during heat treatment under inert and reducing conditions. Heat treatment studies show that the order of stability of the functional groups is quaternary nitrogen > pyridinic > pyrrolic > pyridine N-oxide. Pyridine N-oxide surface groups desorb NO and form N-2 via surface reactions at low temperature. Pyrrolic and pyridinic functional groups decompose and react with surface species to give NH3, HCN, and N-2 as desorption products, but most pyrrolic groups are preferentially converted to pyridinic and quaternary nitrogen. The main desorption product is N-2. Approximately 15-40 wt % of the original nitrogen was retained in the carbons mainly as quaternary nitrogen after heat treatment to 1673 K. The results are discussed in terms of decomposition ranges for surface functional groups and reaction mechanisms of surface species.

Programmazione e controllo dei gruppi pubblici locali. Dagli strumenti esistenti alle soluzioni innovative per la governance.

Il tema dei servizi pubblici locali è sicuramente centrale nell'attuale contesto socio-economico nazionale ed internazionale, in quanto essi hanno un impatto determinante sulle condizioni di vita dei cittadini e sulla competitività dei sistemi economici. In ragione di ciò, negli ultimi anni in Italia numerose riforme si sono susseguite, con lo scopo di individuare l'assetto più efficace ed efficiente per tale settore. Le suddette riforme hanno così ridisegnato il ruolo degli Enti Locali, che saranno sempre meno gestori diretti e sempre più direttori di una multiforme orchestra composta dalle aziende esterne chiamate a fornire in prima persona le prestazioni agli utenti finali. Il presente lavoro si propone di individuare, anche attraverso una ricerca sui Comuni capoluogo di Emilia-Romagna e Toscana, strumenti di programmazione e controllo in ottica di gruppo che consentano agli Enti Locali di svolgere questo nuovo delicato ruolo. Tali strumenti verranno disegnati sulla base delle necessità informative delle amministrazioni indagate e nel rispetto delle più recenti riforme in tema di programmazione, rilevazione, gestione, controllo, valutazione e comunicazione delle performance pubbliche.

Rapid magmatic processes accompany arc-continent collision: the Western Bismarck arc, Papua New Guinea

New U-Th-Ra, major and trace element, and Sr-Nd-Pb isotope data are presented for young lavas from the New Britain and Western Bismarck arcs in Papua New Guinea. New Britain is an oceanic arc, whereas the latter is the site of an arc-continent collision. Building on a recent study of the Manus Basin, contrasts between the two arcs are used to evaluate the processes and timescales of magma generation accompanying arc-continent collision and possible slab detachment. All three suites share many attributes characteristic of arc lavas that can be ascribed to the addition of a regionally uniform subduction component derived from the subducting altered oceanic crust and sediment followed by dynamic melting of the modified mantle. However, the Western Bismarck arc lavas diverge from the Pb isotope mixing array formed by the New Britain and the Manus Basin lavas toward elevated Pb-208/Pb-204. We interpret this to reflect a second and subsequent addition of sediment melt at crustal depth during collision. U-238 and Ra-226 excesses are preserved in all of the lavas and are greatest in the Western Bismarck arc. High-Mg andesites with high Sr/Y ratios in the westernmost arc are attributed to recent shallow mantle flux melting at the slab edge. Data for two historical rhyolites are also presented. Although these rhyolites formed in quite different tectonic settings and display different geochemical and isotopic compositions, both formed from mafic parents within millennia.

The Pinkbow at Backnamullagh

Chamber Orchestra. 6 minutes duration.

Power and Energy Implications of the Number of Threads Used on the Intel Xeon Phi

Energy consumption has become an important area of research of late. With the advent of new manycore processors, situations have arisen where not all the processors need to be active to reach an optimal relation between performance and energy usage. In this paper a study of the power and energy usage of a series of benchmarks, the PARSEC and the SPLASH- 2X Benchmark Suites, on the Intel Xeon Phi for different threads configurations, is presented. To carry out this study, a tool was designed to monitor and record the power usage in real time during execution time and afterwards to compare the r

Precision dating of the Palaeolithic: A new radiocarbon chronology for the Abri Pataud (France), a key Aurignacian sequence

This paper presents a new series of AMS dates on ultrafiltered bone gelatin extracted from identified cutmarked or humanly-modified bones and teeth from the site of Abri Pataud, in the French Dordogne. The sequence of 32 new determinations provides a coherent and reliable chronology from the site's early Upper Palaeolithic levels 5-14, excavated by Hallam Movius. The results show that there were some problems with the previous series of dates, with many underestimating the real age. The new results, when calibrated and modelled using a Bayesian statistical method, allow detailed understanding of the pace of cultural changes within the Aurignacian I and II levels of the site, something not achievable before. In the future, the sequence of dates will allow wider comparison to similarly dated contexts elsewhere in Europe. High precision dating is only possible by using large suites of AMS dates from humanly-modified material within well understood archaeological sequences modelled using a Bayesian statistical method. © 2011.

"No Encores" The Royal Dublin Society Concert Archive Recitals in Retrospect: 1925-50

A large archive of sources for the RDS classical music recitals is extant in the Society’s Library, Ballsbridge, Dublin. The recitals were established in 1886 for the promotion of chamber music and in order to expose Dublin audiences to the works of the great composers. Extant in the collection are minute books; autographed programmes; newspaper cuttings which include previews, reviews and advertisements; correspondences with artists and agents; promotional material; selections of photographs; records of attendance, artists fees and takings; and volumes of printed music.
This paper will document the organisation, management and occurrence of the RDS classical music recitals for the period 1925 to 1950 and will encompass the opening of the current concert hall (The Members’ Hall, 1925), the Society’s bi-centenary celebrations (1931) and the continuance of the recitals within the context of the Second World War (1939- 45). The paper will examine and analyse the following: networks, repertoire and reception.
The RDS music committee established significant links with many performers and UK-based classical music agents. Recitalists include musicians of international renown; Myra Hess, Isolde Menges, Lili Kraus, Joseph Szigeti, Leon Goossens, Sir Hamilton Harty and The Hallé Orchestra, The Catterall Quartet and many local, Dublin-based musicians; Raidió Éireann Orchestra, Dublin String Orchestra, Dublin Philharmonic Orchestra and Culwick Choral Society. The compromises and collaborations in evidence between the music committee, agents and performers resulted in the presentation of varied and well-balanced programmes featuring sonatas, quartets, trios, concerti, overtures, symphonies and songs by composers including Beethoven, Mozart, Haydn and Brahms. Works by contemporary composers including Bax, Dohnanyi, Szymanowski and Suk were also regularly performed, as were works with an Irish influence or flavour. Audiences mainly consisted of members of the Society, music students were encouraged to attend at a reduced rate and reviews were regularly published in the Irish Times, Irish Independent and Irish Press.

An R-matrix approach for plasma modelling and the interpretation of astrophysical observation

Over the last decade an Auburn-Rollins-Strathclyde consortium has developed several suites of parallel R-matrix codes [1, 2, 3] that can meet the fundamental data needs required for the interpretation of astrophysical observation and/or plasma experiments. Traditionally our collisional work on light fusion-related atoms has been focused towards spectroscopy and impurity transport for magnetically confined fusion devices. Our approach has been to provide a comprehensive data set for the excitation/ionization for every ion stage of a particular element. As we progress towards a burning fusion plasma, there is a demand for the collisional processes involving tungsten, which has required a revitalization of the relativistic R-matrix approach. The implementation of these codes on massively parallel supercomputers has facilitated the progression to models involving thousands of levels in the close-coupling expansion required by the open d and f sub-shell systems of mid Z tungsten. This work also complements the electron-impact excitation of Fe-Peak elements required by astrophysics, in particular the near neutral species, which offer similar atomic structure challenges. Although electron-impact excitation work is our primary focus in terms of fusion application, the single photon photoionisation codes are also being developed in tandem, and benefit greatly from this ongoing work.

Comparison of Parallelised R-matrix codes for electron impact excitation of Cr II

A comparison of collision strengths and effective collision strengths has been undertaken for the Cr II ion based on the model of Wasson et al [2010 A & A. 524 A35]. Calculations have been completed using the Breit-Pauli, RMATRX II and DARC suites of codes.

Interacção entre estruturas intervalares e estruturas espectrais, na música instrumental/vocal

A presente tese apresenta-se num formato bipartido, sendo a primeira parte uma investigação teórica e a segunda parte um conjunto de composições originais que procuram estabelecer, directa e indirectamente, uma relação com a temática investigada. A investigação incide sobre as diferentes relações que se podem estabelecer entre estruturas intervalares e estruturas espectrais, a partir de um conjunto representativo de obras de diferentes compositores. As obras originais da segunda parte configuram um objecto final de análise e reflexão. As composições que integram a segunda parte da tese são: Inês – sete miniaturas sobre A Castro, para soprano e orquestra, sobre excertos de “Castro”, de António Ferreira; Um sino contra o tempo, para flauta, clarinete, percussão e piano; Terra, para orquestra de cordas; Dor e Amor, para voz, flauta, clarinete, percussão, harpa, piano, violino, viola e violoncelo, sobre poemas de Nuno Júdice; e Ode a Gaia, para soprano solo, coro misto e electrónica, a partir de textos de diversos autores e épocas, desde Homero a Fernando Pessoa. Esta investigação surge a partir da convicção de que é possível e enriquecedor para a composição a coexistência e o estabelecimento de uma relação entre estruturas que valorizam as qualidades dos intervalos que as constituem e estruturas de tipo espectral. Se o pensamento intervalar pode ser relacionado com princípios de estruturação ligados a toda uma tradição musical, desde a música modal, à tonal e à atonal, o pensamento espectral relaciona-se com o estudo do fenómeno sonoro e do timbre e é integrado mais tardiamente no séc. XX como um possível modelo estruturante na composição. A investigação sobre as obras seleccionadas, sobretudo de compositores que colocam o fenómeno da percepção num plano central, procura diferentes interacções entre os dois tipos de estrutura, interrogando-se sobre em que medida é que essa interacção influencia ou é mesmo determinante para o resultado musical final. São analisadas diferentes aplicações, tais como: a procura de qualidades acústicas na criação de estruturas intervalares, a criação de timbres particulares para linhas estruturantes, a manipulação tímbrica de estruturas verticais, a inter-relação de camadas intervalares e espectrais na textura musical de forma sincrónica e diacrónica, e o surgimento de material intervalar a partir de estruturas espectrais. Os principais resultados passam pela confirmação de que o pensamento intervalar é compatível com o pensamento espectral e vice-versa, podendo-se concluir que são essenciais diferentes funções para os dois tipos de estrutura na textura musical e que quer as estruturas intervalares quer as espectrais se relacionam com diferentes aspectos da percepção, tendo, assim, uma influência determinante no resultado musical final, na eficácia da escuta e na sua fruição.

A construção ilusória da realidade, ressignificação e recontextualização do "Bumba meu boi" do Maranhão a partir da música

A presente tese inscreve-se no domínio da etnomusicologia. Resulta da realização de trabalho de campo no estado do Maranhão/Brasil, entre 2012 e 2014, e propõe um exercício de reflexão sobre as transformações pelas quais passou a prática performativa Bumba meu Boi, a partir da introdução dos instrumentos de sopro na sua componente musical, dando origem ao Boi de Orquestra. Parti do estudo etnográfico dos quatro principais estilos de Bumba meu Boi (sotaques) existentes antes da criação do Boi de Orquestra, e de uma pesquisa de cunho histórico que buscou o modo como esta prática se configurou já no século XX e como ela se traduz na performance (folguedo). Argumento que a criação do sotaque de orquestra favoreceu a aceitação do folguedo pela elite social do Maranhão, que o identificou como próximo da cultura europeia, da qual se sentia caudatária. O repertório performativo analisado neste trabalho inclui as toadas, as danças, as indumentárias e os rituais de batizado e morte do boi, a partir dos registros sonoros e visuais efetuados no mês de junho e julho de 2013. Desta forma, este trabalho procura contribuir para a compreensão do lugar que a música ocupou nos movimentos gerados pelos povos subjugados no período pós-colonial, na luta pela afirmação do seu direito à existência singular. Neste sentido serão analisados os processos de ressignificação e de recontextualização do Bumba Meu Boi e da música, enquanto dispositivos que, no caso do Maranhão, contribuíram para a construção de mundos comuns a partir da criação de realidades ilusórias.

A importância da prática de orquestra no ensino especializado da música : implicações no âmbito da motivação para a aprendizagem instrumental

A ideia inicial para esta investigação era estudar o efeito da prática de orquestra na motivação intrínseca dos alunos, nomeadamente as repercussões no estudo individual do instrumento. Foram realizados dois estudos no contexto da investigação: um primeiro estudo de natureza exploratória, no qual foram entrevistados 15 professores e 15 alunos; um segundo estudo, de natureza descritiva e explanatória, no qual se administraram 274 questionários a alunos de 9 classes de orquestra em 4 escolas do ensino especializado da música, assistiu-se a um ensaio de cada uma das orquestras e realizou-se uma entrevista informal ao professor de cada classe de orquestra. Os resultados obtidos indicam que a prática orquestral pode produzir efeitos na motivação dos alunos, com implicações claras no estudo do instrumento. Também foi possível concluir que a participação dos alunos em orquestra poderá ser um fator capaz de motivar os alunos, e capaz de transformar para melhor a perspetiva dos alunos em relação à aprendizagem musical. Este facto sugere que a prática de orquestra deve ser entendida como um pilar fundamental da dinâmica das escolas do ensino especializado da música, e como uma disciplina nuclear do curriculum deste ensino.

Measurement of Donnan potentials in gels by in situ microelectrode voltammetry

This work describes the electrochemical methodology for the determination of the Donnan potential from diffusion-limited steady-state voltammograms of acrylamide gels. The technique is based upon the measurement of gel–sol systems that have reached Donnan equilibrium and contain Cd2+ as a probe ion. Au-amalgam microelectrodes are used to measure the Cd concentration in the gel phase relative to the solution phase, thus permitting comparison of the Cd voltammograms obtained in both phases. This approach yields two independent measures of the Donnan potential resulting from (i) the potential shift relative to the reference electrode, and (ii) the enhancement of the Cd2+ wave. Two suites of acrylamide gels containing 0.2% and 0.5% Na-acrylate were studied as a function of ionic strength by varying [NaNO3] and maintaining a constant concentration of the electroactive probe ion, [Cd2+] = 1 · 10 5 mol/L in the equilibrating solutions. Independent model predictions of the Donnan potential as a function of ionic strength that consider the effects of differential swelling on the charge density, the influence of a mixed electrolyte on the potential developed in the gel at the limit of low ionic strength and the effects of incomplete dissociation of the carboxylic functional groups were in agreement with the Donnan potentials independently measured by the twofold steady-state voltammetric approach.

Programming multicores safely : handling barrier deadlocks

Tese de doutoramento, Informática (Ciências da Computação), Universidade de Lisboa, Faculdade de Ciências, 2015