Charge transfer at organic heterojunctions: electronic structure and molecular assembly

Ziel dieser Arbeit war es, den grundlegenden Mechanismus des Ladungstransfers bei molekularer Dotierung an organisch-organischen Grenzflächen besser zu verstehen. Es wurde eine Vielfalt modernster spektroskopischer Methoden eingesetzt, um die elektronische Struktur und neue dotierungsinduzierte CT-Übergänge zu ergründen. Dazu gehören UPS und XPS für Valenzsignaturen und Kernniveauzustände. Absorptionsspektroskopie im UV-vis-NIR und Röntgenbereich wurde zur Bestimmung der Übergangsenergien eingesetzt. Schwingungsspektroskopie wurde eingesetzt, um den CT-Grad in DA-Systemen für gestapelte und gemischte Heteroübergänge zu quantifizieren. Strom-Spannungs-Messungen wurden zur Bestimmung der elektrischen Leitfähigkeit und Rasterkraftmikroskopie zur Charakterisierung der Oberflächenmorphologie eingesetzt. Die in dieser Arbeit behandelten Themen sind: (1) Planare Heteroübergänge aus DIP und F6TCNNQ wurden hergestellt. Sie wurden im Hinblick auf CT-Komplexbildung, Grenzflächendotierung und Exzitonenbindungsenergien an der D|A-Grenzfläche untersucht. (2) DBTTF wurde mit TCNNQ und F6TCNNQ in Lösung und in dünnen Filmen gemischt. Daraus wurde der Zusammenhang zwischen Dotierungsmechanismen, CTC- und IPA-Bildung, mit dem Aggregatzustand hergeleitet. (3.1) Rubren-Einkristalle wurden mit Mo(tfd)3 und CoCp2 p- und n-dotiert. Nach der Dotierung verschiebt sich die Banddispersion entsprechend, wohingegen die effektive Masse der Löcher konstant bleibt. (3.2) DBTTF-Einkristalle wurden mit TCNNQ, F6TCNNQ und Mo(tfd)3 dotiert. Aus den Änderungen der elektronischen Struktur wurden der CT über die D|A-Grenzfläche sowie die Dichte der Oberflächenzustände quantifiziert. (4) Von drei DA-Systemen mit unterschiedlicher GS-Wechselwirkungsstärke, DIP:C60, DIP:PDIR-CN2 und DIP|F6TCNNQ, wurden die Grenzflächenexzitonen charakterisiert. Ein Vergleich verschiedener Modelle, die die optische CTC Absorption aus dem DA-Energieniveauoffset beschreiben und abschätzen können, rundet die Ergebnisse ab.The aim of this thesis was to enhance the understanding of the charge transfer mechanism during molecular doping at organic-organic interfaces. A wide range of state-of-the-art spectroscopic methods was employed to unravel the electronic structure and new CT transitions resulting from doping. This includes UPS and XPS for valence signatures and core level states. Absorption spectroscopies in the UV-vis-NIR and X-ray regions were used to determine transition energies. Vibrational spectroscopy was employed to quantify the CT degree in DA systems for stacked and mixed heterojunctions. Current-voltage measurements were used for the determination of electrical conductivities and scanning force microscopy for surface morphology characterization. The topics covered in this thesis are: (1) Planar heterojunctions of DIP and F6TCNNQ were fabricated. They were studied with regard to CT complex formation, interface doping and exciton binding energies at the D|A interface. (2) DBTTF was blended with TCNNQ and F6TCNNQ in solution and in thin films. From this, the connection of the two doping mechanisms, CTC and IPA formation, to the state of matter was derived. (3.1) Rubrene single crystals were p- and n-doped with Mo(tfd)3 and CoCp2. After doping, the band dispersion shifts accordingly, while the hole effective mass stays constant. (3.2) DBTTF single crystals were doped with TCNNQ, F6TCNNQ and Mo(tfd)3. From changes in the electronic structure, the CT across the D|A interface as well as the density of surface states were quantified. (4) From three DA systems with varying GS interaction strength, DIP:C60, DIP:PDIR–CN2 and DIP|F6TCNNQ, the interfacial excitons were characterized. A comparison of different models, which describe and allow to estimate the optical absorption in CTCs from the DA energy level offset, concludes the results

Letter from Paul Beyer to Heinrich Himmler on the Uses of Dowsing Rods, April 3, 1940

Dr. P. Beyer explains to Himmler the uses for dowsing rods and offers examples of success using dowsing rods to locate oil and gas deposits, water, mineral deposits and to avoid lightning.https://digitalcommons.ursinus.edu/dowsing/1004/thumbnail.jp

Letter from Paul Beyer to Heinrich Himmler, July 12, 1940

In this letter, Dr. Paul Beyer writes to Heinrich Himmler, Reichsführer-SS and Head of the German Police regarding the confiscation of literature related to dowsing and pendula. He relates his attempts to address the confiscation with Dr. Koch of the Ministry of Public Enlightenment and Propaganda, who ordered the confiscation. He requests that Himmler abolish the program and proposes the creation of a department dealing specially with dowsing questions which would benefit from Himmler\u27s protection.https://digitalcommons.ursinus.edu/dowsing/1010/thumbnail.jp

Embedding smooth and formal diffeomorphisms through the Jordan-Chevalley decomposition

In [Xiang Zhang, The embedding flows of $C^{\infty}$ hyperbolic diffeomorphisms, J. Differential Equations 250 (2011), no. 5, 2283-2298] Zhang proved that any local smooth hyperbolic diffeomorphism whose eigenvalues are weakly nonresonant is embedded in the flow of a smooth vector field. We present a new, simpler and more conceptual proof of such result using the Jordan-Chevalley decomposition in algebraic groups and the properties of the exponential operator. We characterize the hyperbolic smooth (resp. formal) diffeomorphisms that are embedded in a smooth (resp. formal) flow. We introduce a criterium showing that the presence of weak resonances for a diffeomorphism plus two natural conditions imply that it is not embeddable. This solves a conjecture of Zhang. The criterium is optimal, we provide a method to construct embeddable diffeomorphisms with weak resonances if we remove any of the conditions.Comment: 25 page

Incentivos para produção de habilitação de interesse social: um olhar sobre o Plano Diretor de Florianópolis

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Urbanismo, História e Arquitetura da Cidade, Florianópolis, 2015.A habitação é uma necessidade primária, básica e permanente. Além de necessidade, é um direito universal e constitucional. A produção de habitação e o habitar podem se dar de diversas formas culturais, sociais e econômicas, e assim também podem ser variados os seus impactos no meio. Ao mesmo tempo, quase toda a habitação produzida hoje pode ser entendida como social, se associarmos a esta definição a necessidade de financiamento para a produção de moradia. No Brasil e em boa parte do mundo, as políticas públicas voltadas à habitação não conseguem reverter o cenário de aumento do déficit qualitativo e quantitativo, e menos ainda, dos problemas que a necessidade de habitação traz ao processo de crescimento e expansão das cidades. Neste sentido, Florianópolis não foge à regra geral, enfrentando problemas como invasão de áreas de preservação ambiental, carência de terras para promoção de Habitação de Interesse Social, segregação sócio espacial, formação e expansão de assentamentos precários e expansão urbana em ritmo mais acelerado do que a infraestrutura de suporte para tal. Com a função de reger a ocupação e o uso do solo de Florianópolis, o novo Plano Diretor de Florianópolis começou a ser debatido em 2006, sendo aprovado em janeiro de 2014. Estabelece como horizonte um cenário de crescimento populacional dos atuais cerca de 500 mil habitantes para mais de 750 mil em 2030. Suas diretrizes se propõe como mais justas e equilibradas, voltadas a inovações que contemplem os anseios do presente e do futuro, em termos de desenvolvimento urbano planejado. Esta dissertação discute a questão habitacional no município de Florianópolis, analisando os aspectos de políticas públicas, especialmente de planejamento urbano, cadeia produtiva e sustentabilidade, com foco na produção de Habitação de Interesse Social. Nesta perspectiva a análise do novo Plano Diretor de Florianópolis, contraposta ao Plano anterior permite evidenciar que o mais recente, embora avance em alguns aspectos, tais como como a previsão de AEIS e a definição de faixas de atendimento para HIS, não pode ser caracterizado como inovador, especialmente se considerar os aspectos relativos ao direito à moradia digna e desenvolvimento sustentável. Conforme encontramos em autores como Rolnik, Maricato e Lucini, e como já se desenha no Estatuto da Cidade, tanto o custo da terra quanto o lucro privado não devem ser máximas absolutas que não possam ser equilibradas pela ação do Estado, intervindo na dinâmica econômica, produtiva e mercadológica das cidades, construindo em conjunto com os diversos atores desta dinâmica, cidades mais democráticas e melhores de se viver. A análise do caso de Florianópolis reforça a existência de potencial para a produção de HIS pelo mercado, tirando os instrumentos do discurso e avaliando sua efetivação na prática, e fazendo as correções necessárias para o alcance das metas para as quais foram propostos. Nenhum instrumento de planejamento será útil se não for colocado em prática. A construção da cidade, no sentido mais literal, deve refletir e ser reflexo da sua política habitacional. Várias alternativas para a viabilização de Habitação de Interesse Social e de um Habitar mais sustentável podem vir de Planos Diretores indo além do discurso, atuando de forma proativa, como plano de ação, e assim abrir um enorme leque de oportunidades de troca com a cadeia produtiva. É necessário colocar a Habitação no centro da agenda da política urbana lançando um olhar convergente entre as políticas públicas, o planejamento urbano e as regras que regem a cadeia produtiva, pautada no direito à moradia, na cidade e nas pessoas.Housing is a primary, basic and permanent need. Beyond the need, it is a universal and constitutional right. Housing production and dwelling can happen in different cultural, social and economic ways, as much as can be varied the environment impact it may cause. Almost all housing production today can be understood as social, if we regarded from the view point of production and funding raised. In Brazil as worldwide, most of the public housing policies having not being able to reverse the increasing deficit scenario in our days, neither qualitative nor quantitative, let alone the problems associated with housing demand in the context urban expansion and city growing. Florianopolis is no exception to this general rule, facing a rage variety of problems, from land´s invasion of the environmental persevered areas, the city lack of aproprieted land support for social housing , urban social-spatial segregation, up to the faster growing rate of the slums and urban expansion, without the increase of supporting infrastructure. It was very recent, since 2006, that a new master plan for Florianopolis has being introduced within the local government´s agenda. It was approved as a local urban police, late in January 2014. The new master plan goal sets land use and occupation as a general regulation for the city growth as a whole. They were established considering a population growth ?scenario aimed to foresee an increase from nearly 500 thousand inhabitants to more than 750 thousand in 2030. Their guidelines are supposed to stress a much fair social approach for a better land use balanced. The aim is to build innovative ways for local action and urban planning strategies to answer the ongoing social claims, in as much as the future ones. This is regarding not only environment imbalance, as much as social inequality within the context of Brazilian recent urban and economic development. This research work aims to investigate the social housing agenda within the local government´s context of Florianopolis, analyzing urban policies, especially in connection with new urban planning strategies and regulations. It also attempts to address the relationship between the private housing market and social housing production´s chain, as much as their relationship with some relevant aspects of social housing sustainability and production. It analyses Florianopolis´ new master plan, comparing and opposing the new strategies as stated, in relation to the previous ones. This allows to put in evidence that the new strategies although making some advances, regarding social housing needs, such as a more precise definition of Special Land Using for Social Needs - ?AEIS? and introducing new services´ ranges for social housing, can not be featured as innovative public polices for local government action. This is particularly evident if considering acceptable patterns for sustainable social housing production in relations to human rights. As many Brazilian urban experts such as Rolnik, Maricato and Lucini state in their critical debate and also as the Brazilian Urban Federal Law, better known as ?Estatuto da Cidade? (City´s Constitution Law) already recognises and states, the land´s cost and the private profit should not be the absolute highlights. They needed to be balanced by State action, intervening in the local economy, adjusting the city´s building market dynamics, bringing together the various social actors and the whole range of diverse interests within this dynamic process, towards a more democratic management and social inclusion for a better living city. The case study of Florianopolis have made possible to analyse and put in evidence urban aspects and tools that show the potential of using these new urban polices and local government strategies, regarding social housing production in connection with private market management. For that to happen it seems to be needed some adjustments in the local government´s political agenda and action, taking off the instruments from the speech and evaluating its practical validation. Therefore, making the necessary corrections to achieve the goals for which they have being proposed. No planning tool will be useful if not put into practice. The building of the city, in most literal sense, should not only reflect but also be a reflection of its housing policy. Several alternatives for the viability of social housing and a more sustainable living can come from master plans, if one can go beyond the usual political speech approaching, acting proactively as action plan, and thus open up a huge range of exchange opportunities, within the local context of the production chain. In order for that to happen it seems necessary to put the social housing in the centre of the local urban agenda. That is by building a convergent view between public policy, urban planning and the adjustments needed in the rules of the production chain, based on housing rights, on the city´s rights and on people´s right to the city, thus empowering social action.<br

Phosphate Coordination in a Water-Oxidizing Cobalt Oxide Electrocatalyst Revealed by X-ray Absorption Spectroscopy at the Phosphorus K-Edge

In the research on water splitting at neutral pH, phosphorus-containing transition metal oxyhydroxides are often employed for catalyzing the oxygen evolution reaction (OER). We investigated a cobalt–phosphate catalyst (CoCat) representing this material class. We found that CoCat films prepared with potassium phosphate release phosphorus in phosphate-free electrolytes within hours, contrasting orders of magnitude’s faster K+ release. For P speciation and binding mode characterization, we performed technically challenging X-ray absorption spectroscopy experiments at the P K-edge and analyzed the resulting XANES and EXAFS spectra. The CoCat-internal phosphorus is present in the form of phosphate ions. Most phosphate species are likely linked to cobalt ions in Co–O–PO3 motifs, where the connecting oxygen could be a terminal or bridging ligand in Co-oxide fragments (P–Co distance, ~3.1 Å), with additional ionic bonds to K+ ions (P–K distance, ~3.3 Å). The phosphate coordination bond is stronger than the ionic K+-binding, explaining the strongly diverging ion release rates of phosphate and K+. Our results support a structural role of phosphate in the CoCat, with these ions binding at the margins of Co-oxide fragments, thereby limiting the long-range material ordering. The relations of catalyst-internal phosphate ions to cobalt’s redox-state changes, proton transfer, and catalytic activity are discussed

In situ unsaturated zone water stable isotope (2H and 18O) measurements in semi-arid environments: A soil water balance

© 2016 Author(s). Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil water were measured in the field using a liquid water isotope analyzer (tunable off-axis integrated cavity output spectroscope, OA-ICOS, LGR) and commercially available soil gas probes (BGL-30, UMS, Munich) in the semi-arid Cuvelai-Etosha Basin (CEB), Namibia. Results support the applicability of an in situ measurement system for the determination of stable isotopes in soil pore water. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring-down laser spectroscopic isotope analysis (CRDS, L2120-i, Picarro Inc.). After drift and span correction of the in situ isotope data, precision for over 140 measurements taken during two consecutive field campaigns (June and November 2014) was 1.8 and 0.48 &permil; for δ2H and δ18O, respectively. Mean measurement trueness is determined using quality check standards and was 5 and 0.3 ‰ for δ2H and δ18O, respectively. The isotope depth profiles are used quantitatively to calculate a soil water balance. The contribution of transpiration to total evapotranspiration ranged between 72 and 92 %. Shortly after a rain event, the contribution of transpiration was much lower, at 35 to 50 %. Potential limitations of such an in situ system are related to environmental conditions which could be minimized by using a temperature-controlled chamber for the laser spectrometer. Further, the applicability of the system using previously oven-dried soil material might be limited by physicochemical soil properties (i.e., clay minerals). Uncertainty in the in situ system is suggested to be reduced by improving the calibration procedure and further studying fractionation effects influencing the isotope ratios in the soil water, especially at low water contents. Furthermore, the influence of soil-respired CO2 on isotope values within the root zone could not be deduced from the data