59 research outputs found

    Musiktheorie als interdisziplinĂ€res Fach: 8. Kongress der Gesellschaft fĂŒr Musiktheorie Graz 2008

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    Im Oktober 2008 fand an der UniversitĂ€t fĂŒr Musik und darstellende Kunst Graz (KUG) der 8. Kongress der Gesellschaft fĂŒr Musiktheorie (GMTH) zum Thema »Musiktheorie als interdisziplinĂ€res Fach« statt. Die hier vorgelegten gesammelten BeitrĂ€ge akzentuieren Musiktheorie als multiperspektivische wissenschaftliche Disziplin in den Spannungsfeldern Theorie/Praxis, Kunst/Wissenschaft und Historik/Systematik. Die sechs Kapitel ergrĂŒnden dabei die Grenzbereiche zur Musikgeschichte, MusikĂ€sthetik, zur Praxis musikalischer Interpretation, zur kompositorischen Praxis im 20. und 21. Jahrhundert, zur Ethnomusikologie sowie zur Systematischen Musikwissenschaft. Insgesamt 45 AufsĂ€tze, davon 28 in deutscher, 17 in englischer Sprache, sowie die Dokumentation einer Podiumsdiskussion zeichnen in ihrer Gesamtheit einen höchst lebendigen und gegenwartsbezogenen Diskurs, der eine einzigartige Standortbestimmung des Fachs Musiktheorie bietet.The 8th congress of the Gesellschaft fĂŒr Musiktheorie (GMTH) took place in October 2008 at the University for Music and Dramatic Arts Graz (KUG) on the topic »Music Theory and Interdisciplinarity«. The collected contributions characterize music theory as a multi-faceted scholarly discipline at the intersection of theory/practice, art/science and history/system. The six chapters explore commonalties with music history, music aesthetics, musical performance, compositional practice in twentieth- and twenty-first-century music, ethnomusicology and systematic musicology. A total of 45 essays (28 in German, 17 in English) and the documentation of a panel discussion form a vital discourse informed by contemporaneous issues of research in a broad number of fields, providing a unique overview of music theory today. A comprehensive English summary appears at the beginning of all contributions

    Roadmap for optical tweezers

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    ArtĂ­culo escrito por un elevado nĂșmero de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboraciĂłn, si le hubiere, y los autores pertenecientes a la UAMOptical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space explorationEuropean Commission (Horizon 2020, Project No. 812780

    Advanced 1,2,3-triazolate-based coordination compounds: from carbonic anhydrase mimics, molecular building blocks, and catalyst supports to electrically conducting spin-crossover MOFs

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    Kuratowski complexes and related metal-organic frameworks (MOF), especially of the MFU-4-type, built from 1,2,3-triazolate-based ligands gained increasing interest in the last years due to their variable side ligands and metal sites. Such materials and their post-synthetic modifications have shown an outstanding potential for applications such as adsorption, capture, separation and kinetic trapping of gases, drug delivery, atmospheric water harvesting, sensing, H2/D2 quantum sieving, investigation of fundamental magnetic phenomena, and in particular catalysis. In this respect, MFU-4-type MOF catalysts were shown to outperform other heterogeneous catalysts for the dimerization and polymerization of olefins with some applications already advancing toward commercial applicability. This thesis mainly aims to extend the functionality of 1,2,3-triazolate-based coordination materials via advanced linker designs, novel framework assembly strategies, and post-synthetic modifications, as well as through a better understanding of the underlying material properties. During this project, several new organic and complex building blocks, as well as advanced framework structures were prepared and characterized. Furthermore, additional emphasis was directed to the investigation and interpretation of resulting physical phenomena like phase transitions, magnetism, and electrical conductivity. The Zn-MFU-4l ([Zn5IICl4(BTDD)3]; H2-BTDD = bis(1H-1,2,3-triazolo[4,5-b][4â€Č,5â€Č-i])dibenzo[1,4]dioxin) and Co-MFU-4l ([Zn1.3IICo3.7IICl4(BTDD)3]) metal-organic frameworks were prepared according to the literature procedures and modified by a post-synthetic side ligand exchange of the chloride anions, which led to MFU-4-type structures featuring organometallic metal-carbon bonds. Overall, five new Zn-MFU-4l structures of the general formula [Zn5IILxCl4–x(BTDD)3] (4 ≄ x > 3; L = methanido, ethanido, n-butanido, tert-butanido, 3,3-dimethyl-1-butyn-1-ido; Zn-MFU-4l-Me, -Et, -n-Bu, -t-Bu, -Butyne) and two new Co-MFU-4l structures, Co-MFU-4l-Me ([Zn1.5IICo3.5IIMe3.1Cl0.9(BTDD)3]) and Co-MFU-4l-OH ([Zn1.4IICo3.6II (OH)3.1Cl0.9(BTDD)3]), were obtained. Such side ligands were not characterized for MFU-4-type MOFs before, although they are presumed responsible for the metal site activation during olefin catalysis reactions, which require organometallic co-catalysts. For this purpose, a combination of simulated and measured IR spectra was developed as well-suited characterization technique for such insoluble materials, which preclude analytical methods like liquid state NMR and mass spectroscopy. A high stability of the organometallic Zn-MFU-4l derivatives was observed, whereas the Co-MFU-4l-Me was of a pyrophoric nature and reacted upon water contact to Co-MFU-4l-OH, which exhibited a CO2 binding mechanism comparable to that of carbonic anhydrase. Synthesis of Kuratowski complexes built from 1H-benzotriazole-5,6-diamine (H-btda) ligands and post-synthetic exchange of the chloride side ligands with Tp/Tp* (Tp= hydrotris(pyrazolyl)borate; Tp* = hydrotris(3,5-dimethyl-1-pyrazolyl)borate) provided us with a variety of six-fold diamine-functionalized molecular building blocks intended for the development of novel MOF construction pathways. Crystallization of those compounds have already led to the assembly of porous metal hydrogen-bonded frameworks (M-HOF), some of which have even exhibited permanent porosity. This is a rare property of this material class, which is still in its infancy with only a few structures reported so far. Overall, five new metal hydrogen-bonded framework assemblies (CFA-20-X ((2,6-lutidinium)+[Zn5X4(btda)6X]−· n(DMF); X= Cl−, Br−), CFA-20-Tp, CFA-20-Tp*, CFA-20-Tp*-DMSO ([Zn5Y4(btda)6]; Y = Tp, Tp*) could be characterized, thus representing a significant contribution to this field of study. Although no MOFs could be crystallized from reactions of these complexes with metal salts, preliminary results have shown that direct incorporation of metal sites is a suitable pathway to convert M-HOFs into more stable MOFs. Taking the functionality of MFU-4-type frameworks to the next level, the novel 1,1',5,5'-tetrahydro-6,6'-biimidazo[4,5-f]benzotriazole (H4-bibt) ligand was developed to potentiate the post-synthetic modification possibilities compared to other MFU-4-type frameworks via introduction of additional and easily accessible biimidazole coordination sites at the linker backbone. This gave rise to the five most sophisticated MFU-4-type structures prepared so far. Post-synthetic Tp ligand exchange in the resulting MFU-4-type CFA-19 ([Co5IICl4(H2-bibt)3]) provided the stable CFA-19-Tp ([Co5IICl0.4Tp3.6(H2-bibt)3]) framework, in which the additional coordination sites were saturated in a third modification step with MIBr(CO)3 (M= Re, Mn) moieties or deprotonated via introduction of ZnEt moieties. The resulting materials exhibit high metal site density single-crystal X-ray structures with over 1700 atoms per unit cell for the ReBr(CO)3@CFA-19-Tp ([Co5IICl0.4Tp3.6(H2-bibt)3·(ReIBr(CO)3)2.8]) and a thermally induced release of all CO ligands for the MnBr(CO)3@CFA-19-Tp ([Co5IICl0.4Tp3.6(H2-bibt)3(MnIBr(CO)3)3]·3.1(MnIBr(CO)X)). Preliminary results also indicate a facile incorporation of other coordination moieties such as MIICl2 (M= PdII, PtII). These proof-of-principle incorporations of coordination moieties and open metal sites render such CFA-19-type scaffolds promising supports for an even larger variety of active species intended for the binding and activation of small molecules in future investigations. Coincidental synthesis of the novel CFA-23 ((((propan-2-yl)oxidanium)+[Mn6IICl5(ta)8]−; H-ta= 1H-1,2,3-triazole) coordination framework provided the opportunity to investigate changes of the resulting magnetic properties in comparison to a similar structure built from 1H-1,2,3-benzotriazole, as well as the ultra-narrow character of the pore channels in CFA-23. High purity samples of the literature-known Fe(ta)2 (H-ta= 1H-1,2,3-triazole) framework were prepared and investigated in detail to unveil its record hysteresis spin-crossover phase transition. Aiming at the use of Fe(ta)2 in surface acoustic wave-based sensor applications, experimental and theoretical insights into the material’s electrical conductivity changes upon adsorption of inert gases were assisted with the measurement of adsorption isotherms and the determination of the resulting isosteric enthalpies of adsorption

    Phase formation, hydration behavior, and pressure response of sulfide and thiophosphate solid electrolytes

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    Rechargeable lithium ion batteries (LIB) have become an essential part of our daily lives in recent decades, powering mobile phones, laptops, cordless power tools, and even automobiles. While LIB technology currently dominates the battery market for these mobile applications, its physicochemical power and energy density limit will be reached soon. The use of a solid electrolyte instead of a liquid electrolyte in LIBs promises higher energy density, safer operation, and faster charging. Although the benefits of an all-solid-state battery (ASSB) are enormous, certain prerequisites for solid electrolyte application must be met in order for ASSBs to be technologically and commercially competitive. Ionic conductivity is arguably the most important performance indicator of a solid electrolyte. This thesis introduces the concept of LIBs and ASSBs, as well as fundamentals of battery performance and ion conduction in solids, an overview of material classes with a focus on sulfide- and thiophosphate-based solid electrolytes. Furthermore, the techniques used to characterize the solid electrolytes presented in this thesis are introduced. This work presents several design strategies for improving the ionic conductivity of solid electrolytes based on sulfides and thiophosphates. Bottom-up and top-down post-synthetic modification approaches, thermally and chemically induced phase transitions, and microstructure modifications cover a wide range of length scales

    Roadmap for optical tweezers

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    Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration.journal articl

    Dynamic light scattering on macroscopic particles

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    Viele Annahmen, die die Grundlage der Methodik der Dynamischen Lichtstreuung (DLS) formen, gelten nicht fĂŒr Partikel, deren TeilchengrĂ¶ĂŸe die WellenlĂ€nge des Lichts um mehrere GrĂ¶ĂŸenordnungen ĂŒbersteigt. In dieser Arbeit wird auf das bestehende DLS Konzept eingegangen und bezĂŒglich der Anwendbarkeit auf makroskopische Partikel hinterfragt. Da InhomogenitĂ€ten und OberflĂ€chenstrukturen makroskopischer Teilchen mit der WellenlĂ€nge von gestreutem Licht auflösbar sind, wird die PartikeloberflĂ€che als zusĂ€tzliches, eigenstĂ€ndiges Streuobjekt betrachtet. Dementsprechend ist nicht nur ein Zerfall der Korrelationsfunktion durch Bewegungen der makroskopischen Teilchen relativ zu einander gegeben, sondern auch durch die Bewegung der OberflĂ€chenstreuzentren. In DLS Experimenten mit einzelnen, makroskopischen Kugeln kann mindestens ein vollstĂ€ndiger Zerfall der Autokorrelationsfunktion festgestellt werden. Die Existenz eines zweiten Zerfalls auf kleineren Zeitskalen basiert auf der KomplexitĂ€t der OberflĂ€chenstruktur des Partikels. Der spĂ€te Zerfall, welcher der Translation des Teilchens zugeordnet wird, wird im Rahmen von Anzahlfluktuationseffekten evaluiert. Formulierungen zur Analyse des detektierten IntensitĂ€tssignals des gestreuten Lichts, sowie zur Beschreibung der resultierenden Autokorrelationsfunktion, werden gezeigt. Die Entstehung des Zerfalls auf kleinen Zeitskalen, der sich auf die Bewegung der OberflĂ€chenelemente bzgl. des Partikelschwerpunkts zurĂŒckfĂŒhren lĂ€sst, wird mithilfe eines entwickelten Modells erlĂ€utert. Verschiedene Szenarien bzgl. der Rotationsachse des Teilchens und variierender Parameter werden diskutiert. Das Modell wird experimentell auf seine GĂŒltigkeit ĂŒberprĂŒft. Aus den gewonnenen Erkenntnissen kann schlussendlich in einem finalen Beispielexperiment die granulare Translations- sowie Rotationstemperatur gewonnen werden

    Roadmap for Optical Tweezers 2023

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    Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nanoparticle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration

    Carbon Nanodots from an In Silico Perspective

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    Carbon nanodots (CNDs) are the latest and most shining rising stars among photoluminescent (PL) nanomaterials. These carbon-based surface-passivated nanostructures compete with other related PL materials, including traditional semiconductor quantum dots and organic dyes, with a long list of benefits and emerging applications. Advantages of CNDs include tunable inherent optical properties and high photostability, rich possibilities for surface functionalization and doping, dispersibility, low toxicity, and viable synthesis (top-down and bottom-up) from organic materials. CNDs can be applied to biomedicine including imaging and sensing, drug-delivery, photodynamic therapy, photocatalysis but also to energy harvesting in solar cells and as LEDs. More applications are reported continuously, making this already a research field of its own. Understanding of the properties of CNDs requires one to go to the levels of electrons, atoms, molecules, and nanostructures at different scales using modern molecular modeling and to correlate it tightly with experiments. This review highlights different in silico techniques and studies, from quantum chemistry to the mesoscale, with particular reference to carbon nanodots, carbonaceous nanoparticles whose structural and photophysical properties are not fully elucidated. The role of experimental investigation is also presented. Hereby, we hope to encourage the reader to investigate CNDs and to apply virtual chemistry to obtain further insights needed to customize these amazing systems for novel prospective applications

    Molecules in Superfluid Helium Nanodroplets

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    This open access book covers recent advances in experiments using the ultra-cold, very weakly perturbing superfluid environment provided by helium nanodroplets for high resolution spectroscopic, structural and dynamic studies of molecules and synthetic clusters. The recent infra-red, UV-Vis studies of radicals, molecules, clusters, ions and biomolecules, as well as laser dynamical and laser orientational studies, are reviewed. The Coulomb explosion studies of the uniquely quantum structures of small helium clusters, X-ray imaging of large droplets and electron diffraction of embedded molecules are also described. Particular emphasis is given to the synthesis and detection of new species by mass spectrometry and deposition electron microscopy
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