52,720 research outputs found

    Interactive Sonic Environments: Sonic artwork via gameplay experience

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    The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken

    Metodología de intervención para trabajar ODS. Educación a través de las artes

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    La Agenda 2030 presenta 17 Objetivos de Desarrollo Sostenible (ODS), con sus metas e indicadores universales que los pa√≠ses miembros de la ONU emplean para enmarcar sus pol√≠ticas. Entre las metas del ODS 4 ‚Äúeducaci√≥n de calidad‚ÄĚ encontramos: ‚Äúasegurar que todos los alumnos adquieran los conocimientos te√≥ricos y pr√°cticos necesarios para promover el desarrollo sostenible, entre otras cosas mediante la educaci√≥n para el desarrollo sostenible y los estilos de vida sostenibles, los derechos humanos, la igualdad de g√©nero, la promoci√≥n de una cultura de paz y no violencia, la ciudadan√≠a mundial y la valoraci√≥n de la diversidad cultural y la contribuci√≥n de la cultura al desarrollo sostenible‚ÄĚ. La educaci√≥n, se considera el motor de la Agenda 2030 porque, adem√°s de representar el centro del ODS 4, desempe√Īa tambi√©n un papel notable en la implementaci√≥n de los dem√°s, mejorando su alcance y efectividad. As√≠ pues, entre las disciplinas que sustentan este trabajo se escogi√≥ la Educaci√≥n para el Desarrollo Sostenible y la Ciudadan√≠a Global como marco de acci√≥n y punto de partida en la formaci√≥n de los ciudadanos de un futuro viable, equitativo y habitable. Se continu√≥ investigando las oportunidades del desarrollo de la Competencia Intercultural en las relaciones humanas, aquello que diferencia a unas personas de otras puede aportar al conjunto de la sociedad y c√≥mo la educaci√≥n permitir√≠a su aprovechamiento. Con todo ello, se plante√≥ el marco did√°ctico de interacci√≥n en el cual se implement√≥ la interculturalidad en el ejercicio educativo. Se estudi√≥ as√≠ el poder de las artes como medio de motivaci√≥n e inspiraci√≥n a la hora de transmitir de la manera m√°s eficaz posible los valores considerados m√°s arriba. El objetivo del presente estudio se centra en demostrar el potencial de las artes para fomentar las competencias comunicativas, sociales, interculturales, emocionales, de ciudadan√≠a y sostenibilidad. Para ello, se ha realizado una investigaci√≥n aplicada que deriva en una propuesta concreta de intervenci√≥n con un programa educativo destinado a la ense√Īanza de lenguas, tanto primera como extranjera, en distintos niveles de la educaci√≥n formal en Mali y en Espa√Īa, aplicando un m√©todo hol√≠stico basado en el paradigma interpretativo. A trav√©s de la pintura, la literatura y el cine, se plantean una serie de actividades ideadas para crear un entorno educativo integrador, favorecer el empoderamiento del alumnado y promover el pensamiento cr√≠tico, la empat√≠a, la resiliencia, la comunicaci√≥n, la cooperaci√≥n y la educaci√≥n intercultural, como competencias esenciales para la consecuci√≥n de los 17 ODS, la construcci√≥n de un mundo transcultural sostenible y el desarrollo de una ciudadan√≠a global preparada para los retos del siglo XXI. En la metodolog√≠a de este proceso educativo innovador, multidisciplinar, flexible y adaptable, se ha empleado un an√°lisis del proceso de investigaci√≥n para monitorizarlo adecuadamente (DAFO). Cada una de las propuestas presenta una recogida de datos cualitativos (observaci√≥n, r√ļbricas) y cuantitativos (encuestas, entrevistas) y se ofrece un an√°lisis de contraste de los resultados finales. Con todo, se espera facilitar la exigente tarea que supone hacer consciente a la sociedad de base (desde la misma infancia; desde los niveles m√°s bajos de la misma y en todos los niveles de la educaci√≥n formal) de en qu√© consisten los ODS y su relevancia para hacer de todas las personas corresponsables directas en su consecuci√≥n para garantizar un futuro sostenible para toda la ciudadan√≠a global.The 2030 Agenda presents 17 Sustainable Development Goals (SDGs), with their universal targets and indicators that UN member countries use to frame their policies. Among the targets of SDG 4 ‚Äúquality education,‚ÄĚ we find the one that seeks: ‚Äúto ensure that all students acquire the theoretical and practical knowledge necessary to promote sustainable development, among other things through education for sustainable development and sustainable lifestyles, human rights, gender equality, the promotion of a culture of peace and non-violence, world citizenship and the appreciation of cultural diversity and the contribution of culture to sustainable development‚ÄĚ. Education is considered the engine of the 2030 Agenda because, in addition to representing the centre of SDG 4, it also plays a notable role in the implementation of the others, improving their scope and effectiveness. Among the disciplines that support this research, Education for Sustainable Development and Global Citizenship sets the framework for action and represents a starting point in the formation of citizens for a viable, equitable and habitable future. Global citizenship implies human relations and those and intrinsically shaped by culture. Intercultural Education and, more specifically, the development of Intercultural Competence needed to be considered. What differentiates some people from others can contribute to society as a whole and education is the means to explore and understand. For the design of a didactic framework of interaction, the power of the arts was studied as a means of motivation and inspiration when transmitting the values considered above in the most effective way possible. The objective of this study focuses on proving the potential of the arts to promote communicative, social, intercultural, emotional, citizenship and sustainability skills. For this, the theoretical research derived in a concrete intervention proposal with an educational program in language teaching, both first and foreign languages, at different levels of formal education in Mali and Spain, applying a holistic method based on the interpretive paradigm. Through painting, literature and cinema, a series of activities were designed to create an inclusive educational environment, favour the empowerment of students and promote critical thinking, empathy, resilience, communication, cooperation and intercultural education, as essential skills for the achievement of the 17 SDGs, the construction of a sustainable transcultural world and the development of global citizenship prepared for the challenges of the 21st century. In the methodology of this innovative, multidisciplinary, flexible and adaptable educational process, an analysis of the research process has been used to adequately monitor it (SWOT). Each of the proposals presents a collection of qualitative data (observation, rubrics) and quantitative data (surveys, interviews) and contrast analysis of the final results is offered. All in all, it is expected to facilitate the demanding task of making basic society aware (from childhood itself, from its lowest levels and at all levels of formal education) of what the SDGs consist of and their relevance to make all people directly co-responsible in its achievement to guarantee a sustainable future for all global citizens

    Self-help/mutual aid groups in mental health : ideology, helping mechanisms and empowerment

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    In the last quarter of the twentieth century, self-help/mutual aid groups for mental health issues started to emerge in growing numbers, mainly in Western societies, offering and/or advocating for alternative non-traditional forms of support, and attracted the attention of many researchers and clinicians for their unique characteristics. Among the subjects of interest are typologies of groups, helping mechanisms and benefits from participation. However, there is lack of systematic research in the area and existing studies have been largely confined to the therapeutic value of these groups instead of acknowledging their socio-political meaning and subsequent psychosocial benefits for their members like personal empowerment. The present study was conducted during the transitional years from a Conservative to a newly elected Labour Government (1996 -1998), with subsequent policy shifts taking place in the welfare sector. The purpose of the study was to explore the potential of self-help groups as part of a broader new social movement, the service user movement, focussing on the English scene. It addressed this issue examining the relevance of a group typology based on political ideology and focus of change. To test the validity of this classification for members, a set of individual characteristics and group mechanisms as well as their change through time were examined. The sample consisted of fourteen mental health selfhelp/mutual aid groups from London and South East England, with a variety of structural and organisational features. The methodology used was a combination of both quantitative (self-completion questionnaires) and qualitative techniques (analysis of written material, participant observation and interviews). Measurements were repeated after a one-year interval (Time 1N=67, Time 2 N=56). Findings showed that, indeed, political ideology of self-help/mutual aid groups provided the basis of a meaningful typology and constitutes a comprehensive way of categorising them. Group ideology was related to specific helping mechanisms and aspects of personal empowerment. Specifically, conservative and combined group members reported more expressive group processes like sharing of feelings and self-disclosure, while radical group members were more empowered and optimistic. Group identification was also associated with specific helping activities and aspects of empowerment in the three group categories. The psychosocial character of group types and the beneficial outcomes for members remained stable through time. In general, prolonged participation was reflected in greater member identification with the group and resulted in improved mental wellbeing, increased social support, companionship and optimism for the future

    Studies of strategic performance management for classical organizations theory & practice

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    Nowadays, the activities of "Performance Management" have spread very broadly in actually every part of business and management. There are numerous practitioners and researchers from very different disciplines, who are involved in exploring the different contents of performance management. In this thesis, some relevant historic developments in performance management are first reviewed. This includes various theories and frameworks of performance management. Then several management science techniques are developed for assessing performance management, including new methods in Data Envelopment Analysis (DEA) and Soft System Methodology (SSM). A theoretical framework for performance management and its practical procedures (five phases) are developed for "classic" organizations using soft system thinking, and the relationship with the existing theories are explored. Eventually these results are applied in three case studies to verify our theoretical development. One of the main contributions of this work is to point out, and to systematically explore the basic idea that the effective forms and structures of performance management for an organization are likely to depend greatly on the organizational configuration, in order to coordinate well with other management activities in the organization, which has seemingly been neglected in the existing literature of performance management research in the sense that there exists little known research that associated particular forms of performance management with the explicit assumptions of organizational configuration. By applying SSM, this thesis logically derives some main functional blocks of performance management in 'classic' organizations and clarifies the relationships between performance management and other management activities. Furthermore, it develops some new tools and procedures, which can hierarchically decompose organizational strategies and produce a practical model of specific implementation steps for "classic" organizations. Our approach integrates popular types of performance management models. Last but not least, this thesis presents findings from three major cases, which are quite different organizations in terms of management styles, ownership, and operating environment, to illustrate the fliexbility of the developed theoretical framework

    Recent Hong Kong cinema and the generic role of film noir in relation to the politics of identity and difference

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    This thesis identifies a connection in Hong Kong cinema with classical Hollywood film noir and examines what it will call a 'reinvestment' in film noir in recent films. It will show that this reinvestment is a discursive strategy that both engages the spectator-subject in the cinematic practice and disengages him or her from the hegemony of the discourse by decentring the narrative. The thesis argues that a cinematic practice has occurred in the recent reinvestment of film noir in Hong Kong, which restages the intertextual relay of the historical genre that gives rise to an expectation of ideas about social instability. The noir vision that is seen as related to the fixed categories of film narratives, characterizations and visual styles is reassessed in the course of the thesis using Derridian theory. The focus of analysis is the way in which the constitution of meanings is dependent on generic characteristics that are different. Key to the phenomenon is a film strategy that destabilizes, differs and defers the interpretation of crises-personal, social, political and/or cultural-by soliciting self-conscious re-reading of suffering, evil, fate, chance and fortune. It will be argued that such a strategy evokes the genre expectation as the film invokes a network of ideas regarding a world perceived by the audience in association with the noirish moods of claustrophobia, paranoia, despair and nihilism. The noir vision is thus mutated and transformed when the film device differs and defers the conception of the crises as tragic in nature by exposing the workings of the genre amalgamation and the ideological function of the cinematic discourse. Thus, noirishness becomes both an affect and an agent that contrives a self-reflexive re-reading of the tragic vision and of the conventional comprehension of reality within the discursive practice. The film strategy, as an agent that problematizes the film form and narrative, gives rise to what I call a politics of difference, which may also be understood as the Lyotardian 'language game' or a practice of 'pastiche' in Jameson's terminology. Under the influence of the film strategy, the spectator is enabled to negotiate his or her understanding of recent Hong Kong cinema diegetically and extra-diegetically by traversing different positions of cinematic identification. When the practice of genre amalgamation adopts the visual impact of the noirish film form, the film turns itself into a playing field of 'fatal' misrecognition or a site of question. Through cinematic identification and alienation from the identification, the spectator-subject is enabled to experience the misrecognition as the film slowly foregrounds the way in which the viewer's presence is implicated in the narrative. This thesis demonstrates that certain contemporary Hong Kong films introduce this selfconscious mode of explication and interpretation, which solicits the spectator to negotiate his or her subject-position in the course of viewing. The notions of identity and subjectivity under scrutiny will thus be reread. With reference to The Private Eye Blue, Swordsman II, City a/Glass and Happy Together, the thesis shall explore the ways in which the Hong Kong films enable and facilitate a negotiation of cultural identity

    Gendered spaces in contemporary Irish poetry

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    The thrust of this thesis is summarized by the following questions: How does contemporary Irish poetry migrate from traditional conceptions of identity drawn on by the cultural nationalism of the Irish Literary Revival, and what effects does this have on understanding gendered and national identity formation? Chapters are on the following: Seamus Heaney, Tom Paulin, Paul Muldoon, MedbhMcGuckian, Eavan Boland and Sara Berkeley. These poets are chosen for discussion since their work most effectively engages with the relationship between woman and nation, the representation of gendered national identity, and the importance of feminist and post-colonial theorization. Focusing on poetry worth and South of the border from the last fifteen years, the thesis asks how a younger generation of poets provide a response to nationality which is significantly different from their predecessors. The thesis is composed of three parts: the first understand how the male poets depart from conventional conceptions of the nation with reference to post-colonial theorization; the second explores how feminist theorization informs readings of how the female poets respond to the nation; the final part investigates migration in the poetry and problematizes this in terms of post-nationalism. Discussing the issue of deterritorialization in Irish poetry, the thesis notice how as the poets attempt to take flight from the mythologies of nationhood, they undermine the monoliths of gendered and national identity inscribed within Irish political discourse, which is typified at a representative level by the figure of Mother Ireland or Cathleen Ni Houlihan. Investigating the ways in which gender and nation, and the body and space are reinscribed by the poets, the thesis argues that their poetry challenges authentic conceptions of Irish identity and the nation-state, so as to loosen the legacy of a colonial and nationalist inheritance

    Botanical Journeys and China's Colonial Frontiers: 1840-1940

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    Over recent years, a body of scholarship has emerged on the topic of European and American travel writing in China. This thesis contributes to this growing field by examining four writers who travelled in China and worked as plant collectors and botanists. Largely forgotten today, these writers were influential and successful in their own day. Despite differences in geographical location and historical period, there are a number of common links that make a comparison of these travel writings productive. As travellers seeking botanical rarity and novelty, these writers explored regions of China unknown in the West, which over a period of one hundred years expanded outwards from the fringes of the treaty port areas to more remote regions of China's southwest. These writers, therefore, were on the frontiers of Western knowledge of China, and an examination of their writing provides important insights into the ways in which racial, geographical, and ecological differences were articulated and understood in the context of colonial and scientific exploration. While discussing how such differences have imperial significance, this study will also call attention to the instability of colonialist discourse in the context of China. Rather than focus exclusively on questions of imperialism, this study will show how representations of China's periphery regions also speak to metropolitan literary and cultural concerns, and a close reading of these travel writings shows that China offered powerful imaginary landscapes for home audiences. This project is organised chronologically and the chapters are divided according to the authors, with the exception of the first chapter where I introduce the historical and theoretical framework of the study and the final concluding chapter where I consider the significance of this study in the context of modern China

    In search of 'The people of La Manche': A comparative study of funerary practices in the Transmanche region during the late Neolithic and Early Bronze Age (250BC-1500BC)

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    This research project sets out to discover whether archaeological evidence dating between 2500 BC - 1500 BC from supposed funerary contexts in Kent, flanders and north-eastern Transmanche France is sufficient to make valid comparisons between social and cultural structures on either side of the short-sea Channel region. Evidence from the beginning of the period primarily comes in the form of the widespread Beaker phenomenon. Chapter 5 shows that this class of data is abundant in Kent but quite sparse in the Continental zones - most probably because it has not survived well. This problem also affects the human depositional evidence catalogued in Chapter 6, particularly in Fanders but also in north-eastern Transmanche France. This constricts comparative analysis, however, the abundant data from Kent means that general trends are still discernible. The quality and volume of data relating to the distribution, location, morphology and use of circular monuments in all three zones is far better - as demonstrated in Chapter 7 -mostly due to extensive aerial surveying over several decades. When the datasets are taken as a whole, it becomes possible to successfully apply various forms of comparative analyses. Most remarkably, this has revealed that some monuments apparently have encoded within them a sophisticated and potentially symbolically charged geometric shape. This, along with other less contentious evidence, demonstrates a level of conformity that strongly suggests a stratum of cultural homogeneity existed throughout the Transmanche region during the period 2500 BC - 1500 BC. The fact that such changes as are apparent seem to have developed simultaneously in each of the zones adds additional weight to the theory that contact throughout the Transmanche region was endemic. Even so, it may not have been continuous; there may actually have been times of relative isolation - the data is simply too course to eliminate such a possibility

    Der Ligand bestimmt den Cluster: Einfluss und Möglichkeiten zur Modifizierung der Liganden an Goldnanoclustern

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    Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht gepr√ľftAbweichender Titel nach √úbersetzung der Verfasserin/des VerfassersMonolayer-protected gold nanoclusters show interesting catalytic activity, as well as electronic,geometric and chiral properties that are very different from inert bulk gold and therefore of interest for a number of applications. Furthermore, such clusters can be obtained as monodisperse samples, which allows to investigate structure‚Äďproperty relationships. One of the most important factors that influence for example the size and shape, but also the stability, reactivity or chirality in Au nanoclusters are the protecting ligands, for which already a subtle change in the hydrocarbon framework can result in significantly different properties of the cluster species. Understanding and selectively tuning the metal nanoclusters by ligand engineering has thus become an important objective in nanocluster chemistry. Within this thesis, three fields in which protecting ligands play a major role are investigated,namely (1) chirality, (2) synthesis strategies for Au nanoclusters and (3) heterogeneous catalysis.Several species of gold nanoclusters exhibit intrinsic chiral properties, which can be due to chiral Au‚Äďligand interfaces or chiral metal kernels. However, obtaining them as single enantiomers can be a daunting task since it requires specifically tailored separation techniques.Therefore, a direct synthesis approach with a chiral thiol ligand was employed to obtain two intrinsically chiral nanoclusters, Au38 and Au144, for which unusually high yields were achieved, whereas only moderate yields of an achiral Au25 cluster were obtained. Comparison of the circular dichroism spectra to reported single enantiomer Au38 and Au144 spectra indicated that enantiopure samples had been obtained. These results demonstrate that synthesis with chiral ligands is a powerful tool to selectively afford chiral gold nanoclusters in high yield.Furthermore, complementary density functional theory calculations of Au25 and Au38 were carried out to obtain suitable model structures for future investigation of their chiral properties.Another approach for targeted cluster design are ligand exchange induced size/structure transformations, in which a precursor gold cluster is subjected to large amounts of thiolate ligands and thereby selectively converted to a new cluster species of different size and/orgeometry. Applying such a two-phase LEIST process on the water-soluble Au25(SG)13 resulted in phase-transfer and formation of Au16(2-PET)14. Infrared spectroscopy confirmed complete replacement of the protecting ligands, whereas X-ray absorption spectroscopy indicated similar core structures of both clusters. Of note, Au16(2-PET)14 is among the smallest thiolate-protected Au nanoclusters that have been isolated in significant purity, which makes it an interesting compound for studying structural evolution of gold nanoclusters.Finally, also ligand effects in catalysis were investigated by studying CO oxidation as model reaction with Au nanoclusters protected by different types of ligands (phosphines, thiolates,mix of phosphines and thiolates). The lower conversion achieved by clusters with phosphines in the ligand shell compared to the thiolate-protected cluster after oxidative pretreatment at 250 ¬įC was attributed to the accumulation of ligand residues at the cluster‚Äďsupport interface region. These sites are of great importance for the subsequent reaction. In contrast,no significant dependence on the availability of exposed Au surface or the cluster size was observed. This shows that the ligands influence the reactivity of cluster catalysts even after their decomposition, which must therefore be taken into account in the design of a catalytic system.Durch Liganden gesch√ľtzte Goldnanocluster zeigen bemerkenswerte katalytische Aktivit√§t,sowie elektronische, geometrische und chirale Eigenschaften, die sich stark von jenen des unreaktiven Goldes in metallischer Form unterscheiden und dadurch f√ľr eine Vielzahl von Anwendungen attraktiv sind. Zudem k√∂nnen solche Cluster auch monodispers hergestellt werden, was es erm√∂glicht, Struktur‚ÄďWirkungsbeziehungen zu untersuchen. Einer der bedeutendsten Einflussfaktoren auf beispielsweise die Gr√∂√üe und Form, aber auch die Stabilit√§t und Reaktivit√§t oder Chiralit√§t von Goldnanoclustern entsteht durch die Liganden. Bereits eine kleine Ver√§nderung im organischen Rest kann die Clustereigenschaften nachhaltig ver√§ndern. Ein wichtiges Ziel der Goldnanoclusterchemie ist es daher, diese von den Liganden hervorgerufenen √Ąnderungen zu verstehen und gezielt einsetzen zu k√∂nnen. Im Rahmen dieser Arbeit werden drei Bereiche, in denen Clusterliganden eine wichtige Rolle spielen,n√§her untersucht, und zwar (1) Chiralit√§t, (2) Synthesestrategien f√ľr Goldnanocluster und(3) heterogene Katalyse. Einige Goldnanocluster zeigen intrinsisch chirale Eigenschaften, die durch chirale Au‚ÄďLiganden Schnittstellen und/oder durch chirale Kernstrukturen hervorgerufen werden. Es ist jedoch oftmals ein kompliziertes Unterfangen, die Cluster als reine Enantiomere zu erhalten,da es den Einsatz speziell angepasster Separationstechniken erfordert. Daher wurde eine direkte Synthesestrategie mit einem chiralen Thiolliganden eingesetzt und zwei verschiedene intrinsisch chirale Nanocluster, n√§mlich Au38 und Au144, in ungew√∂hnlich hoher Ausbeute erhalten, wohingegen kein Anstieg in der Menge des erhaltenen achiralen Au25 Clusters beobachtet werden konnte. Ein Vergleich der gemessenen Circular Dichroism Spektren mit publizierten Spektren einzelner Enantiomere von Au38 und Au144 deutete darauf hin,dass enantiomerenreine Clusterproben erhalten wurden. Das zeigt, dass Direktsynthese mit chiralen Liganden ein sehr wirksames Mittel ist, um gezielt chirale Goldnanocluster in hoher Ausbeute zu erhalten.Zudem wurden auch Dichtefunktionalrechnungen der Au25 und Au38 Cluster durchgef√ľhrt,mit dem Ziel, geeignete Modellstrukturen f√ľr die weitere Untersuchung ihrer chiralen Eigenschaften zu erhalten. Zielgerichtetes Clusterdesign l√§sst sich aber beispielsweise auch durch sogenannte Ligandenaustausch-induzierte Gr√∂√üe/Struktur Transformationen bewerkstelligen. Dabei wird ein Ausgangscluster einer gro√üen Menge an Thiolatliganden ausgesetzt und dadurch selektiv in einen anderen Cluster von unterschiedlicher Gr√∂√üe und/oder Geometrie √ľberf√ľhrt.F√ľhrt man einen solchen Austauschprozess als Zweiphasenreaktion (Wasser und organisches L√∂sungsmittel) mit dem wasserl√∂slichen Au25(SG)13 als Edukt durch, erfolgt ein Phasentransfer und die Bildung von Au16(2-PET)14. Infrarotspektroskopie zeigte, dass die Ligandenkomplett ausgetauscht wurden, wohingegen R√∂ntgenabsorptionsspektroskopie auf √§hnliche Kerngeometrien der beiden Cluster hinwies. Bei Au16(2-PET)14 handelt es sich um einen der kleinsten Thiolat-gesch√ľtzen Goldnanocluster, die bisher in entsprechender Reinheit isoliert werden konnten. Das macht es zu einer interessanten Verbindung, um die strukturelle Evolution dieser Cluster zu untersuchen. Zuletzt wurden auch Ligandeneffekte in der Katalyse untersucht. Hierf√ľr wurde eine COOxidations-Modellreaktion mit Goldnanoclustern, die mit unterschiedlichen Arten von Liganden (Phosphine, Thiolate bzw. eine Mischung der beiden) in ihrer Struktur aufweisen,untersucht. Die geringere Umsetzung von CO mit den Clustern, die Phosphine in ihrer Ligandenaschale aufweisen, im Vergleich zum Thiolat-gesch√ľtzten Clusterkatalysator nach oxidativer Vorbehandlung bei 250 ¬įC wurde auf die Ansammlung von Liganden√ľberresten im Bereich der Schnittstelle zwischen Cluster und Tr√§germaterial zur√ľckgef√ľhrt. Diese Positionen sindbei der CO Oxidation von gro√üer Bedeutung. Im Gegensatz dazu konnte keine Abh√§ngigkeitvon der Verf√ľgbarkeit freier Goldoberfl√§che oder der Clustergr√∂√üe nachgewiesen werden. Das zeigt, dass die Liganden die Reaktivit√§t von Clusterkatalysatoren beeinflussen, auch wenn sie bereits durch Vorbehandlung zersetzt wurden und muss daher beim Design des Katalysatorsystems ber√ľcksichtigt werden.20

    Speciation of organoarsenicals in aqueous solutions by Raman spectrometry and quantum chemical calculations

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    .Knowledge about the existence and stability of different species of organoarsenicals in solution is of the most significant interest for fields so different as chemical, environmental, biological, toxicological and forensic. This work provides a comparative evaluation of the Raman spectra of four organoarsenicals (o-arsanilic acid, p-arsanilic acid, roxarsone and cacodylic acid) in aqueous solutions under acidic, neutral and alkaline conditions. Speciation of some of these organoarsenicals is possible by Raman spectrometry at different selected pHs. Further, we examine the proficiency of computational chemistry to obtain the theoretical Raman spectra of the four organoarsenicals compounds. To this end, we employ a computational protocol that includes explicit water molecules and conformational sampling, finding that the calculated organoarsenicals spectra agree reasonably well with those experimentally obtained in an aqueous solution in the whole pH range covered. Finally, we highlight the effectiveness of quantum chemical calculations to identify organoarsenicals in an aqueous solution.S
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