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Contains fulltext : 159612.pdf (Publisher’s version ) (Closed access)

Contains fulltext : 170785.pdf (Publisher’s version ) (Closed access) Social and gender governance has emerged primarily at the national and global level, but more recently and to a more modest extent it has emerged at the regional level as well. Four regional social and gender regimes can be distinguished because regional organizations selectively have adopted and “regionalized” ILO and UN standards of gender equality, labor rights, and social protection. Against the background of mobilization against globalization and the “neo-liberal” character of regionalism, it is striking that there is only a piecemeal development towards more regional social policy-making. Sovereignty concerns of states, the lack of access for non-state actors, the weakness of regional institutions, and the strength or weakness of national welfare regimes all act as constraints on the development of more comprehensive and enforceable social and gender governance at the regional level.

Contributing to a critical re-examination of multi-stakeholder governance, this chapter conducts an in-depth analysis of business-civil society interaction in the Roundtable on Sustainable Biofuels (RSB). Inquiring into the causes of a deliberation failure, the chapter identifies a high level of politicization as well as the background role of the state as the underlying factors. It is uncovered how deep-seated divisions and ideologically charged conflicts limited the opportunity for meaningful deliberative governance in the biofuels arena. In addition, it is shown how the European Union undermined the position of the RSB through endorsing a non-participatory model of private sustainability governance in this policy area. This reduced the pressure on biofuel companies to engage in difficult interactions with critical NGOs in the RSB.

We present the first in situ W-band (94-GHz) electron paramagnetic resonance (EPR) study of a trapped electron center in thin MgO(001) films. The improved resolution of the high-field EPR experiments proves that the signal originate from a well-defined species present in the bulk of the films, whose projection of the principal g-tensor components onto the (001) plane are oriented along the [110] direction of the MgO lattice. Based on a comparison between the structural properties of the films, knowledge of the ability of bulk defects to trap electrons, and the properties of the EPR signal, it is possible to propose that the paramagnetic species are located at the origin of a screw dislocation in the bulk of the film.

The present work considers vanadium oxides catalysts in the selective oxidation of small alkanes. The dynamics of their (surface) electronic structure modulated by the chemical potential of reaction gases were investigated regarding charge carrier dynamics, surface valence/conduction band structure and work function modifications. The charge carrier dynamics were studied with the in situ microwave cavity perturbation technique allowing the determination of the catalyst conductivity in a contact free manner in a fixed bed reactor geometry. An evaluation program based on the transmission line theory was developed for precise conductivity determination. The validity of the evaluation methods was tested with the n-type semiconducting vanadium pentoxide in the oxidation of n-butane. In agreement with literature, the experiments revealed an n-type conductivity. The addition of n-butane in the reaction feed leads to an increased conductivity corresponding to the abundance of electronically active V4+ defect states (corresponding to oxygen vacancies) in the forbidden bandgap of vanadium pentoxide increasing the mobile electron density. Based on results of the reference study, the selective propane oxidation catalyst MoVNbTeO x M1-phase was investigated in the selective oxidation of ethane, propane and n-butane. Also the impact of water in the propane feed, triggering the abundance of the industrially important key product acrylic acid, on the MoVNbTeOx M1-phase electronic structure was studied. The in situ microwave cavity perturbation studies at ambient pressure were complemented with near ambient pressure X-ray photoelectron and X-ray absorption spectroscopy investigations at 0.25 mbar to understand the charge transfer processes according to semiconductor physics. The conductivity of MoVNbTeOx M1-phase increased with increasing propane to oxygen ratio identifying MoVNbTeOx M1-phase as an n-type semiconductor. In the alkane (ethane, propane and n-butane) exchange experiment, the number of electrons transferred to MoVNbTeOx M1-phase increased from ethane, to propane and finally to n-butane oxidation resulting in an increased conductivity. The X-ray photoelectron spectroscopy reveals that the exchange of the alkane leads to a modulation of the V4+/V5+ redox couple at the surface corresponding to shifts of the valence band edge and electron affinity. Thus the surface of MoVNbTeOx M1-phase, being in dynamic equilibrium with the bulk electronic structure, is modified by the compositions (corresponding to the chemical potential) of the gas phase. The bulk charge carrier density is triggered by the barrier height of the surface induced space charge layer resulting in a modified conductivity. In contrast the modulated electron affinity can be explained by a change of the surface dipole. Water in propane feed leads to a decreased conductivity of MoVNbTeOx M1-phase without a modification of the space charge layer. A drastic change of the surface elemental composition, in particular the abundance of V5+ , is induced by water, observable in the valence band, core level and vanadium L2,3-edges X-ray absorption spectra. The surface modifications were accompanied with a decreased electron affinity corresponding to a decreased surface dipole. The drastically changed valence and conduction band structure likely affects the charge carrier mobility explaining the decreased conductivity in steam containing propane feed. However, results from low pressure in situ photoelectron studies are debated according to their relevance for "real" catalysis at ambient pressures. In particular the oxygen pressure controls the oxidation state of transition metal oxide surfaces. The vanadium L2,3 X-ray absorption edges of vanadyl pyrophosphate were investigated in the selective n-butane oxidation at 10, 100 and 1000 mbar to identify a possible pressure gap using the surface sensitive conversion electron mode. As a result, at low pressures the oxidation of the surface is controlled by the oxygen pressure. In contrast at higher pressures, the surface state of oxidation is triggered by the catalytic reaction providing a steady state between reduction of the catalyst during n-butane conversion and re-oxidation by molecular oxygen.

Sowohl die katalytische Methanol- als auch Ammoniaksynthese spielen in der chemischen Industrie eine große Rolle. Beide Chemikalien werden als Plattformmolekül in Größenordnungen von mehreren Millionen Tonnen jährlich hergestellt. Beide Moleküle werden zurzeit aufgrund ihres vorteilhaften C zu H Verhältnisses sowie einfachen Handhabbarkeit im flüssigen Zustand als alternative Wasserstoffträger diskutiert. Die heterogen katalysierten Synthesen von Methanol und Ammoniak werden als struktursensitiv bezeichnet, da sie nicht auf jeder Form elementaren Kupfers oder Eisens ablaufen, sondern nur auf mikrostrukturell komplexen, Cu- und Fe-basierten Katalysatoren mit hohen Reaktionsraten. In der Vergangenheit wurden große Anstrengungen unternommen, um Erkenntnisse über aktive Zentren und Reaktionsmechanismen beider Reaktionen zu gewinnen, welche eine erkenntnisbasierte Katalysatoroptimerung ermöglichen sollte. Dabei wurde postuliert, dass Erkenntnisse bzgl. des Zustandes des aktivierten Katalysators unter Umgebungsbedingungen nicht direkt auf Reaktionsbedingungen unter hohen Betriebstemperaturen und mehreren Atmosphären Gasdruck extrapoliert werden können. Bezugnehmend auf das fundamentale Interesse, katalytische Systeme unter nah-industriellen Synthesebedingungen in-situ zu untersuchen, wurde eine Durchflusszelle entwickelt, welche geeignet ist, unter 60-80 bar und 250-425 °C Methanol sowie Ammoniak herzustellen und dabei Neutronendiffraktion und online-Gasanalytik durchzuführen. Basierend auf der Erkenntnis, dass die Aktivität eines Cu-basierten Methanolkatalysators mit der Defektivität der Cu-Nanopartikel korreliert, wurde eine ex-situ Neutronendiffraktionsstudie an Referenzkupfer sowie nanokristallinen Katalysatoren mit zunehmender chemischer und struktureller Komplexität durchgeführt. Zur sorgfältigen Analyse der Streulinienprofile wurde ein Strukturanpassungsmodell verwendet, welches Linienversetzungen, planare Defekte, Domänengrößen, Kristallmorphologie sowie Modalität einschließt und so die Zuordnung der gemessenen Streuintensitäten zu einem speziellen mikrostrukturellen Ursprung ermöglicht. Die Übertragung der Erkenntnisse über die Mikrostruktur aus ex-situ Studien auf in-situ Studien zeigt die Stabilität der planaren Defekte im Cu/ZnO/Al2O3 Methanolkatalysator. Durch diese Ergebnisse, könnte eine Weiterentwicklung des angewandten “Whole-Powder-Pattern“-Modellierungsalgorithmus unter Einbindung der thermischen Auslenkung der Atome sowie Vielfachstreuung -verursacht durch die reaktive Gasatmosphäre- eine noch präzisere Strukturauklärung des Katalysators unter Reaktionsbedingungen ermöglichen. Die Rietveld-Verfeinerungen der in-situ Diffraktogramme des mehrfach-promotierten α-Fe basierten Ammoniakkatalysators unter 75 bar und 425 °C offenbaren die Anwesenheit von Verspannungen im Katalysator über die gesamte Synthesedauer hindurch. Dieses Ergebnis spricht für die Katalysatorpromotierung und -aktivierung als Ursache der Gitterverzerrungen im Kristallgitter des Fe (evtl. durch den Einbau von Fremdatomen). Diese Beobachtungen zeigen, dass die mikrostrukturellen Eigenheiten der untersuchten Katalysatoren, die aus der komplexen und hoch-optimierten Präparationsgeschichte herrühren und für die Aktivität maßgeblich sind, unter harschen Reaktionsbedingungen erhalten bleiben. Die Ergebnisse dieser Arbeit demonstrieren die Leistungsfähigkeit der in-situ Neutronendiffraktion und geben neue Impulse für die Untersuchung der Mikrostruktur arbeitender Katalysatoren unter anspruchsvollen Synthesebedingungen durch die Verknüpfung von Struktur- und Aktivitäts-informationen., The two catalytic methanol- and ammonia synthesis reactions play a major role in chemical industry, both chemicals are produced as platform molecules in millions of metric tons. Both molecules are recently discussed as an alternative hydrogen carrier due to their advantageous C or N to H ratio and feasible handling in their liquid state. Both heterogeneous catalytic processes of methanol and ammonia synthesis are thought to be structure-sensitive reactions, as they don't proceed on every form of elemental Cu or Fe. High rates require special complex Cu and Fe-based catalysts. A large effort was made to distinguish active centres and reaction mechanisms on the used catalyst with the goal of a knowledge-based catalyst optimisation for more efficient synthesis. It has been postulated, that the perceptions of the activated catalyst structure under ambient conditions can't simply be extrapolated to operation conditions at elevated temperatures and pressures. To study the catalytic systems in-situ under near-industrial working conditions, continuous flow cells were constructed, suitable for temperatures from 250 °C to 425 °C and 60 bar to 80 bar pressure which allow the collection of neutron diffraction data and simultaneous on-line gas analysis during catalytic synthesis of methanol and ammonia at industrial conditions. Based on the key finding that the activity of the Cu-based methanol catalyst scales with a certain defectiveness of the nanoparticles, an ex-situ neutron diffraction study on macrocrystalline Cu-powder and nanocrystalline catalyst with increasing chemical and structural complexity was conducted. By careful analysis of the diffraction line profiles a structural fit-model was elaborated, which takes line dislocations, planar defects and domains sizes, crystallite morphology and modality into account, enabling to assign the diffracted intensities in the patterns to a particular microstructural feature of the sample. Projecting the knowledge of the peculiar microstructure from ex-situ studies to in-situ studies under 250 °C and 60 bar reveals the stability of the planar defects in the Cu/ZnO/Al2O3 methanol catalyst. Based on this encouraging proof-of-principle results, further development of the applied convolutional whole-powder-pattern modelling algorithm might allow a more precise structure simulation of operational catalysts in the future, taking thermal displacement of the atoms and multiple or incoherent scattering from the reactive gas phase into account. Rietveld-refinement of the in-situ diffraction data at 425 °C and 75 bar of the operational multiple-promoted a-Fe based ammonia catalyst reveal the presence of strain in varying amounts over entire time on stream, which is indicating that the proposed lattice distortion has formed already as a result of catalyst activation, probably with other atoms in the interstitials of the iron lattice. These findings confirm that the microstructural features of the used catalysts, which are a result of their complex and highly optimized preparation history and are claimed to be relevant for their activity, prevail under harsh near-industrial reaction conditions. The results presented in this thesis demonstrate the capability of in-situ neutron diffraction and give new impulses for the investigation of the microstructure of operational catalysts under demanding reaction conditions by linking structure and performance data.

Carbon can be used as an alternative to metal based catalysts for oxidative dehydrogenation reaction (ODH) of aromatic hydrocarbons, alkanes or alkenes. The active sites of the catalyst are still unknown, but it should be either one or more of the oxygen functional groups. On the other hand, carbon materials are used as catalytic supports for metal particles. The oxygen groups on the support material are the anchoring sites to immobilize the metal particles. The interaction between oxygen groups and metal particles improves the catalytic activity and selectivity of the catalyst. Therefore, functionalization of carbon materials is a very important method, furthermore it is important to know how many different oxygen groups exist on the carbon surface. There is still a big lack of information about the kind of oxygen groups on carbon. Highly oriented pyrolytic graphite (HOPG) is a well-defined model system without any metal impurities and pores. Therefore, the oxygen functionalities on HOPG were studied. To study the nature of the induced oxygen groups, combined Temperature Programmed Desorption (TPD) and X-Ray Photoelectron Spectroscopy (XPS) were used. UV photoelectron spectroscopy (UPS) was applied to monitor the electronic structure and the damage of the HOPG surfaces. The surface morphology was characterized by Scanning Electron Microscopy (SEM) and Scanning Tunneling Microscopy (STM). Since the dissociation rate of oxygen on defect-free HOPG is practically zero, defects were introduced on HOPG by sputtering. Two paths were used: Sputtering with argon in an oxygen- or water-gas atmosphere and sputtering with argon and oxygen itself. Our investigation shows that sputtering with oxygen produces mainly oxygen species in the HOPG matrix. In contrast, sputtering with Ar in oxygen gas atmosphere produces mainly oxygen species in a small amount and these oxygen species are situated on the HOPG surface. The second sputter method is used as the standard method for functionalization of HOPG, with the goal of generating oxygen groups on it. Even though HOPG is a well-defined material, there are various construction defects in the HOPG matrix. Our investigation shows that these minimal differences of the original HOPG structure can be determined with Ar-TPD spectra. Furthermore, this method can be used to assess the HOPG quality. In XPS spectra, various oxygen 1s signals occur only in a narrow range of 2.5 eV and overlap in this range. Thus, it is very difficult to identify single oxygen peaks and assign them clearly. In the literature, O1s peaks are fitted with different numbers of O1s components, but without mentioning why a certain number of oxygen groups is used for O1s-XPS fitting. Our investigation shows clearly, at least five O1s components are necessary to fit the O1s XPS spectra properly. The thermal stability and oxidizability of the oxygen components is used to discuss the character of the oxygen components.

High impact events, political changes and new technologies are reflected in our language and lead to constant evolution of terms, expressions and names. Not knowing about names used in the past for referring to a named entity can severely decrease the performance of many computational linguistic algorithms. We propose NEER, an unsupervised method for named entity evolution recognition independent of external knowledge sources. We find time periods with high likelihood of evolution. By analyzing only these time periods using a sliding window co-occurrence method we capture evolving terms in the same context. We thus avoid comparing terms from widely different periods in time and overcome a severe limitation of existing methods for named entity evolution, as shown by the high recall of 90% on the New York Times corpus. We compare several relatedness measures for filtering to improve precision. Furthermore, using machine learning with minimal supervision improves precision to 94%. Wichtige Ereignisse, politische Veränderungen und neue Technologien spiegeln sich in unserer Sprache wieder und führen zu einer ständigen Evolution von Begriffen, Ausdrücken und Namen. Mangelndes Wissen über frühere Namen einer Entität kann die Leistungsfähigkeit vieler computerlinguistischer Methoden deutlich verringern. In diesem Papier präsentieren wir unsere nichtüberwachte Methode namens NEER zur Erkennung von Namensevolution, die unabhängig von externen Datenquellen arbeitet. Indem wir Zeiträume mit erhöhter Evolutionswahrscheinlichkeit mit Hilfe einer Kookkurrenzmethode basierend auf Sliding Windows-Verfahren untersuchen, erfassen wir evolvierende Terme im selben Kontext. Dadurch vermeiden wir es, Terme aus weit auseinander liegenden Zeiträumen zu vergleichen und umgehen damit eine schwerwiegende Beschränkung vorhandener Methoden. Dieses zeigt sich an einer gemessenen Sensitivität von 90% auf dem Korpus der New York Times. Um die Genauigkeit zu erhöhen, vergleichen wir mehrere Ähnlichkeitsmaße zur Filterung. Mit Hilfe von maschinellem Lernen mit minimaler Überwachung verbessern wir die Genauigkeit auf 94%.

The tutorial discusses the core ideas of building digital libraries on distributed infrastructures and the related architectural options. The main part of the tutorial revolves around how core DL functionality like Digital Library Management, Content and Collection Management, Metadata Management and Brokering, Search and Retrieval and Advanced Services (Personalization, Annotation, etc.) can be built by exploiting P2P and Grid technological frameworks. For each of the topics the key challenges are discussed together with possible solutions for the challenges and the lessons learned in implementing these solutions in concrete projects. The solutions are illustrated with concrete examples and demos from the projects DILIGENT, BRICKS, and DELOS as well as from other DL-related projects. Target Audience: The tutorial is mainly targeted towards researchers and practitioners that are working in the area of digital libraries, digital library architectures, and innovative digital library services. Furthermore, the tutorial will also be an opportunity for other players to gain insights in the area of current developments in the area of next generation digital library architectures and new applications of Grid technology and the Peer-to-peer paradigm. Level of experience required: Introductory to intermediate.

The aim of the BRICKS project is to design, develop and maintain an open user and service-oriented infrastructure to share knowledge and resources in the Cultural Heritage domain. Typical usage scenarios are integrated queries among several knowledge resource, e.g. to discover all Italian artifacts from renaissance in the European museums or to follow the life cycle of historic documents. These examples are specific applications, which are running on top of the BRICKS infrastructure. The BRICKS infrastructure will use the Internet as a backbone and will fulfil the requirements of expandability, graduality of engagement, scalability, availability, and interoperability. In addition, the user community has the economic requirement to be low-cost. This means (1) that an institution should be able to become a BRICKS member with minimal investments, and (2) that the maintenance costs of the infrastructure, and in consequence the running costs of each BRICKS member, are minimised. Also, the BRICKS membership will be flexible, such that parties can join or leave the system at any point in time without administrative overheads. In order to fulfil these requirements the BRICKS architecture will be decentralised, based on a peer-to-peer (P2P) paradigm, i.e. no central server will be employed. Every member institution of a BRICKS installation is a node (a BNode in the BRICKS jargon) of the distributed architecture. The foundation components (bricks, in the BRICKS jargon) making up the BRICKS architecture are Web Services, and provide functionalities for maintaining the system, for contentand metadata management, or security. Applications are composed out of these base components and can add new ones to provide additional functionalities.