@phdthesis{Peng2015,
  author    = {Peng, Lei},
  title     = {Electrochemistry and biocatalysis of new peroxide-activating enzymes},
  school      = {Universit{\"a}t Potsdam},
  pages     = {123},
  year      = {2015},
  language  = {en}
}
@phdthesis{Jung2015,
  author    = {Jung, J{\"o}rg},
  title     = {Efficient credit based server load balancing},
  school      = {Universit{\"a}t Potsdam},
  pages     = {353},
  year      = {2015},
  language  = {en}
}
@phdthesis{Schiess2015,
  author    = {Schiess, Sonja},
  title     = {Effects of glucotropaeolin and its breakdown product benzyl isothiocyanate on metabolic, endocrine, and inflammatory parameters in humans},
  school      = {Universit{\"a}t Potsdam},
  pages     = {115},
  year      = {2015},
  language  = {en}
}
@phdthesis{Grune2015,
  author    = {Grune, Jana},
  title     = {Effects of a novel non-steroidal mineralocorticoid receptor antagonist on cardiac hypertrophy},
  school      = {Universit{\"a}t Potsdam},
  pages     = {98},
  year      = {2015},
  language  = {en}
}
@phdthesis{Obu2015,
  author    = {Obu, Jaroslav},
  title     = {Effect of mass wasting on soil organic carbon storage and coastal erosion in permafrost environments},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90599},
  school      = {Universit{\"a}t Potsdam},
  pages     = {iii, 93},
  year      = {2015},
  abstract  = {Accelerated permafrost thaw under the warming Arctic climate can have a significant impact on Arctic landscapes. Areas underlain by permafrost store high amounts of soil organic carbon (SOC). Permafrost disturbances may contribute to increased release of carbon dioxide and methane to the atmosphere. Coastal erosion, amplified through a decrease in Arctic sea-ice extent, may also mobilise SOC from permafrost. Large expanses of permafrost affected land are characterised by intense mass-wasting processes such as solifluction, active-layer detachments and retrogressive thaw slumping. Our aim is to assess the influence of mass wasting on SOC storage and coastal erosion. We studied SOC storage on Herschel Island by analysing active-layer and permafrost samples, and compared non-disturbed sites to those characterised by mass wasting. Mass-wasting sites showed decreased SOC storage and material compaction, whereas sites characterised by material accumulation showed increased storage. The SOC storage on Herschel Island is also significantly correlated to catenary position and other slope characteristics. We estimated SOC storage on Herschel Island to be 34.8 kg C m-2. This is comparable to similar environments in northwest Canada and Alaska. Coastal erosion was analysed using high resolution digital elevation models (DEMs). Two LIDAR scanning of the Yukon Coast were done in 2012 and 2013. Two DEMs with 1 m horizontal resolution were generated and used to analyse elevation changes along the coast. The results indicate considerable spatial variability in short-term coastline erosion and progradation. The high variability was related to the presence of mass-wasting processes. Erosion and deposition extremes were recorded where the retrogressive thaw slump (RTS) activity was most pronounced. Released sediment can be transported by longshore drift and affects not only the coastal processes in situ but also along adjacent coasts. We also calculated volumetric coastal erosion for Herschel Island by comparing a stereo-photogrammetrically derived DEM from 2004 with LIDAR DEMs. We compared this volumetric erosion to planimetric erosion, which was based on coastlines digitised from satellite imagery. We found a complex relationship between planimetric and volumetric coastal erosion, which we attribute to frequent occurrence of mass-wasting processes along the coasts. Our results suggest that volumetric erosion corresponds better with environmental forcing and is more suitable for the estimation of organic carbon fluxes than planimetric erosion. Mass wasting can decrease SOC storage by several mechanisms. Increased aeration following disturbance may increase microbial activity, which accelerates organic matter decomposition. New hydrological conditions that follow the mass wasting event can cause leaching of freshly exposed material. Organic rich material can also be directly removed into the sea or into a lake. On the other hand the accumulation of mobilised material can result in increased SOC storage. Mass-wasting related accumulations of mobilised material can significantly impact coastal erosion in situ or along the adjacent coast by longshore drift. Therefore, the coastline movement observations cannot completely resolve the actual sediment loss due to these temporary accumulations. The predicted increase of mass-wasting activity in the course of Arctic warming may increase SOC mobilisation and coastal erosion induced carbon fluxes.},
  language  = {en}
}
@phdthesis{Timofeeva2015,
  author    = {Timofeeva, Nadezda},
  title     = {Effect of ions and amino-acid sequence on collagen structure},
  school      = {Universit{\"a}t Potsdam},
  pages     = {121},
  year      = {2015},
  language  = {en}
}
@phdthesis{Radenacker2015,
  author    = {Radenacker, Anke},
  title     = {Economic consequences of family dissolution},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100217},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 134},
  year      = {2015},
  abstract  = {Welfare states and policies have changed greatly over the past decades, mostly characterized by retrenchments in terms of government spending or in terms of restricted access to certain benefits. In the area of family policies, however, a lot of countries have simultaneously expanded provisions and transfers for families. Bringing together the macro analysis of policy variation and household income changes on the micro-level, the main research question of the dissertation is to what extent economic consequences following separation and divorce in families with children have changed between the 1980s and the 2000s in Germany and the United States. The second research question of the dissertation regards the differences in dissolution outcomes between married and cohabiting parents in Germany. The dissertation thus aims to link institutional regulations of welfare states with the actual income situation of families. To achieve this, a research design was developed that has never been used for the analysis of the economic consequences of family dissolution. For this, the two longest running panel datasets, German Socio-economic Panel (GSOEP) and the US American Panel Study of Income Dynamics (PSID), have been used. The analytic strategy applied to estimate the effects of family dissolution on household income is a difference-in-difference design combined with coarsened exact matching (CEM). To begin with, the dissertation confirmed many findings of previous research, for example regarding the gender differences in family dissolution outcomes. Mothers experience clearly higher relative income losses and consequently higher risks of poverty than fathers. This finding is universal, that is it holds for both countries, for all time periods observed, and for all measures of economic outcome that were employed. Another confirmed finding is the higher level of welfare state intervention in Germany compared to the United States. The dissertation also revealed a number of novel findings. The results show that the expansion of family policies in Germany over time has not been accompanied by substantially decreasing income losses for mothers. Though income losses have slightly decreased over time, they have become more persistent during the years following family dissolution. The impact of the German welfare state has meanwhile been quite stable. American mothers' income losses took place on a slightly lower level than those of German mothers. Only during the 1980s their relative losses were clearly lower than those of German mothers. And also American mothers did not recover as much from their income losses during the 2000s than they used to during the 1980s. For them, the 1996 welfare reform brought a considerable decrease in welfare state support. Accordingly, the results for American mothers can certainly be described as a shift from public to private provision. The general finding of previous studies that fathers do not have to suffer income losses, or if at all rather moderate ones compared to mothers, can be confirmed. Nevertheless, both German and US American fathers face a deterioration of the economic consequences of family dissolution over time. German fathers' relative income changes are still positive though they have decreased over time. One reason for this decrease is the increasing loss of partner earnings following union dissolution. Also among American fathers, income gains still prevail in the year of family dissolution. Two years later, however, they have been facing income losses already since the 1980s which have furthermore increased considerably over time. Zooming in on Germany, family dissolution outcomes by marital status show negligible differences between cohabiting and married mothers in disposable income, but considerable differences in losses of income before taxes and transfers. It is the impact of the welfare state that equalizes the differences in income losses between these two groups of mothers. For married mothers, losses are not as high in the year of event but they have difficulties to recover from these losses. Without the income buffering of the welfare state, married mothers would, three years after family dissolution, remain with relative income losses double as high as for cohabiting mothers. Compared to mothers, differences between married and cohabiting fathers are visible in changes of income before as well as after taxes and transfers. The welfare state does not alter the difference between the two groups of fathers. With regard to both income concepts, cohabiting fathers fare worse than married fathers. Cohabiting fathers suffer moderate income losses of disposable income while married fathers experience moderate income gains. Accounting for support payments is decisive for fathers' income changes. If these payments are not deducted from disposable income, both married and cohabiting fathers experience gains in disposable income following family dissolution.},
  language  = {en}
}
@phdthesis{Shivanand2015,
  author    = {Shivanand, Lathe Rahul},
  title     = {DUF1068 protein family members are involved in cell wall formation in Arabidopsis thaliana},
  school      = {Universit{\"a}t Potsdam},
  pages     = {393},
  year      = {2015},
  language  = {en}
}
@phdthesis{Ogone2015,
  author    = {Ogone, James Odhiambo},
  title     = {Domesticating modernity in Africa},
  school      = {Universit{\"a}t Potsdam},
  pages     = {229},
  year      = {2015},
  language  = {en}
}
@phdthesis{Baumeier2015,
  author    = {Baumeier, Christian},
  title     = {Dietary and Pharmacological Strategies for the Prevention and Treatment of Type 2 Diabetes in a Diabetes-Susceptible Mouse Model},
  school      = {Universit{\"a}t Potsdam},
  pages     = {148},
  year      = {2015},
  language  = {en}
}
@phdthesis{Priegnitz2015,
  author    = {Priegnitz, Mike},
  title     = {Development of geophysical methods to characterize methane hydrate reservoirs on a laboratory scale},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89321},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 99},
  year      = {2015},
  abstract  = {Gashydrate sind kristalline Feststoffe bestehend aus Wasser und Gasmolek{\"u}len. Sie sind stabil bei erh{\"o}hten Dr{\"u}cken und niedrigen Temperaturen. Nat{\"u}rliche Hydratvorkommen treten daher an Kontinentalh{\"a}ngen, in Permafrostb{\"o}den und in tiefen Seen sowie Binnenmeeren auf. Bei der Hydratbildung orientieren sich die Wassermolek{\"u}le neu und bilden sogenannte K{\"a}figstrukturen, in die Gas eingelagert werden kann. Aufgrund des hohen Drucks bei der Hydratbildung k{\"o}nnen große Mengen an Gas in die Hydratstruktur eingebaut werden. Das Volumenverh{\"a}ltnis von Wasser zu Gas kann dabei bis zu 1:172 bei 0°C und Atmosph{\"a}rendruck betragen. Nat{\"u}rliche Gashydrate enthalten haupts{\"a}chlich Methan. Da Methan sowohl ein Treibhausgas als auch ein Brenngas ist, stellen Gashydrate gleichermaßen eine potentielle Energieressource sowie eine m{\"o}gliche Quelle f{\"u}r Treibhausgase dar. Diese Arbeit untersucht die physikalischen Eigenschaften von Methanhydrat ges{\"a}ttigten Sedimentproben im Labormaßstab. Dazu wurde ein großer Reservoirsimulator (LARS) mit einer eigens entwickelten elektrischen Widerstandstomographie ausger{\"u}stet, die das erste Mal an hydratges{\"a}ttigten Sedimentproben unter kontrollierten Temperatur-, Druck-, und Hydrats{\"a}ttigungsbedingungen im Labormaßstab angewendet wurde. {\"U}blicherweise ist der Porenraum von (marinen) Sedimenten mit elektrisch gut leitendem Salzwasser gef{\"u}llt. Da Hydrate einen elektrischen Isolator darstellen, ergeben sich große Kontraste hinsichtlich der elektrischen Eigenschaften im Porenraum w{\"a}hrend der Hydratbildung und -zersetzung. Durch wiederholte Messungen w{\"a}hrend der Hydraterzeugung ist es m{\"o}glich die r{\"a}umliche Widerstandsverteilung in LARS aufzuzeichnen. Diese Daten bilden in der Folge die Grundlage f{\"u}r eine neue Auswerteroutine, welche die r{\"a}umliche Widerstandsverteilung in die r{\"a}umliche Verteilung der Hydrats{\"a}ttigung {\"u}berf{\"u}hrt. Dadurch ist es m{\"o}glich, die sich {\"a}ndernde Hydrats{\"a}ttigung sowohl r{\"a}umlich als auch zeitlich hoch aufgel{\"o}st w{\"a}hrend der gesamten Hydraterzeugungsphase zu verfolgen. Diese Arbeit zeigt, dass die entwickelte Widerstandstomographie eine gute Datenqualit{\"a}t aufwies und selbst geringe Hydrats{\"a}ttigungen innerhalb der Sedimentprobe detektiert werden konnten. Bei der Umrechnung der Widerstandsverteilung in lokale Hydrat-S{\"a}ttigungswerte wurden die besten Ergebnisse mit dem Archie-var-phi Ansatz erzielt, der die zunehmende Hydratphase dem Sedimentger{\"u}st zuschreibt, was einer Abnahme der Porosit{\"a}t gleichkommt. Die Widerstandsmessungen zeigten weiterhin, dass die schnelle Hydraterzeugung im Labor zur Ausbildung von kleinen Hydratkristallen f{\"u}hrte, die dazu neigten, zu rekristalliesieren. Es wurden weiterhin Hydrat-Abbauversuche durchgef{\"u}hrt, bei denen die Hydratphase {\"u}ber Druckerniedrigung in Anlehnung an den 2007/2008 Mallik Feldtest zersetzt wurde. Dabei konnte beobachtet werden, dass die Muster der Gas- undWasserflussraten im Labor zum Teil gut nachgebildet werden konnten, jedoch auch aufbaubedingte Abweichungen auftraten. In zwei weiteren Langzeitversuchen wurde die Realisierbarkeit und das Verhalten bei CO2-CH4-Hydrat Austauschversuchen in LARS untersucht. Das tomographische Messsystem wurde dabei genutzt um w{\"a}hrend der CH4 Hydrat Aufbauphase die Hydratverteilung innerhalb der Sedimentprobe zu {\"u}berwachen. Im Zuge der anschließenden CO2-Injektion konnte mithilfe der Widerstandstomographie die sich ausbreitende CO2-Front {\"u}berwacht und der Zeitpunkt des CO2 Durchbruchs identifiziert werden.},
  language  = {en}
}
@phdthesis{Laemke2015,
  author    = {L{\"a}mke, J{\"o}rn},
  title     = {Determining the future in the past},
  school      = {Universit{\"a}t Potsdam},
  pages     = {149},
  year      = {2015},
  language  = {en}
}
@phdthesis{Boesche2015,
  author    = {B{\"o}sche, Nina Kristine},
  title     = {Detection of rare earth elements and rare earth oxides with hyperspectral spectroscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85363},
  school      = {Universit{\"a}t Potsdam},
  pages     = {147},
  year      = {2015},
  abstract  = {The continuously increasing demand for rare earth elements in technical components of modern technologies, brings the detection of new deposits closer into the focus of global exploration. One promising method to globally map important deposits might be remote sensing, since it has been used for a wide range of mineral mapping in the past. This doctoral thesis investigates the capacity of hyperspectral remote sensing for the detection of rare earth element deposits. The definition and the realization of a fundamental database on the spectral characteristics of rare earth oxides, rare earth metals and rare earth element bearing materials formed the basis of this thesis. To investigate these characteristics in the field, hyperspectral images of four outcrops in Fen Complex, Norway, were collected in the near-field. A new methodology (named REEMAP) was developed to delineate rare earth element enriched zones. The main steps of REEMAP are: 1) multitemporal weighted averaging of multiple images covering the sample area; 2) sharpening the rare earth related signals using a Gaussian high pass deconvolution technique that is calibrated on the standard deviation of a Gaussian-bell shaped curve that represents by the full width of half maxima of the target absorption band; 3) mathematical modeling of the target absorption band and highlighting of rare earth elements. REEMAP was further adapted to different hyperspectral sensors (EO-1 Hyperion and EnMAP) and a new test site (Lofdal, Namibia). Additionally, the hyperspectral signatures of associated minerals were investigated to serve as proxy for the host rocks. Finally, the capacity and limitations of spectroscopic rare earth element detection approaches in general and of the REEMAP approach specifically were investigated and discussed. One result of this doctoral thesis is that eight rare earth oxides show robust absorption bands and, therefore, can be used for hyperspectral detection methods. Additionally, the spectral signatures of iron oxides, iron-bearing sulfates, calcite and kaolinite can be used to detect metasomatic alteration zones and highlight the ore zone. One of the key results of this doctoral work is the developed REEMAP approach, which can be applied from near-field to space. The REEMAP approach enables rare earth element mapping especially for noisy images. Limiting factors are a low signal to noise ratio, a reduced spectral resolution, overlaying materials, atmospheric absorption residuals and non-optimal illumination conditions. Another key result of this doctoral thesis is the finding that the future hyperspectral EnMAP satellite (with its currently published specifications, June 2015) will be theoretically capable to detect absorption bands of erbium, dysprosium, holmium, neodymium and europium, thulium and samarium. This thesis presents a new methodology REEMAP that enables a spatially wide and rapid hyperspectral detection of rare earth elements in order to meet the demand for fast, extensive and efficient rare earth exploration (from near-field to space).},
  language  = {en}
}
@phdthesis{TorresAcosta2015,
  author    = {Torres Acosta, Ver{\´o}nica},
  title     = {Denudation processes in a tectonically active rift on different time scales},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84534},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xv, ix, 183},
  year      = {2015},
  abstract  = {Continental rifts are excellent regions where the interplay between extension, the build-up of topography, erosion and sedimentation can be evaluated in the context of landscape evolution. Rift basins also constitute important archives that potentially record the evolution and migration of species and the change of sedimentary conditions as a result of climatic change. Finally, rifts have increasingly become targets of resource exploration, such as hydrocarbons or geothermal systems. The study of extensional processes and the factors that further modify the mainly climate-driven surface process regime helps to identify changes in past and present tectonic and geomorphic processes that are ultimately recorded in rift landscapes. The Cenozoic East African Rift System (EARS) is an exemplary continental rift system and ideal natural laboratory to observe such interactions. The eastern and western branches of the EARS constitute first-order tectonic and topographic features in East Africa, which exert a profound influence on the evolution of topography, the distribution and amount of rainfall, and thus the efficiency of surface processes. The Kenya Rift is an integral part of the eastern branch of the EARS and is characterized by high-relief rift escarpments bounded by normal faults, gently tilted rift shoulders, and volcanic centers along the rift axis. Considering the Cenozoic tectonic processes in the Kenya Rift, the tectonically controlled cooling history of rift shoulders, the subsidence history of rift basins, and the sedimentation along and across the rift, may help to elucidate the morphotectonic evolution of this extensional province. While tectonic forcing of surface processes may play a minor role in the low-strain rift on centennial to millennial timescales, it may be hypothesized that erosion and sedimentation processes impacted by climate shifts associated with pronounced changes in the availability in moisture may have left important imprints in the landscape. In this thesis I combined thermochronological, geomorphic field observations, and morphometry of digital elevation models to reconstruct exhumation processes and erosion rates, as well as the effects of climate on the erosion processes in different sectors of the rift. I present three sets of results: (1) new thermochronological data from the northern and central parts of the rift to quantitatively constrain the Tertiary exhumation and thermal evolution of the Kenya Rift. (2) 10Be-derived catchment-wide mean denudation rates from the northern, central and southern rift that characterize erosional processes on millennial to present-day timescales; and (3) paleo-denudation rates in the northern rift to constrain climatically controlled shifts in paleoenvironmental conditions during the early Holocene (African Humid Period). Taken together, my studies show that time-temperature histories derived from apatite fission track (AFT) analysis, zircon (U-Th)/He dating, and thermal modeling bracket the onset of rifting in the Kenya Rift between 65-50 Ma and about 15 Ma to the present. These two episodes are marked by rapid exhumation and, uplift of the rift shoulders. Between 45 and 15 Ma the margins of the rift experienced very slow erosion/exhumation, with the accommodation of sediments in the rift basin. In addition, I determined that present-day denudation rates in sparsely vegetated parts of the Kenya Rift amount to 0.13 mm/yr, whereas denudation rates in humid and more densely vegetated sectors of the rift flanks reach a maximum of 0.08 mm/yr, despite steeper hillslopes. I inferred that hillslope gradient and vegetation cover control most of the variation in denudation rates across the Kenya Rift today. Importantly, my results support the notion that vegetation cover plays a fundamental role in determining the voracity of erosion of hillslopes through its stabilizing effects on the land surface. Finally, in a pilot study I highlighted how paleo-denudation rates in climatic threshold areas changed significantly during times of transient hydrologic conditions and involved a sixfold increase in erosion rates during increased humidity. This assessment is based on cosmogenic nuclide (10Be) dating of quartzitic deltaic sands that were deposited in the northern Kenya Rift during a highstand of Lake Suguta, which was associated with the Holocene African Humid Period. Taken together, my new results document the role of climate variability in erosion processes that impact climatic threshold environments, which may provide a template for potential future impacts of climate-driven changes in surface processes in the course of Global Change.},
  language  = {en}
}
@phdthesis{Meyer2015,
  author    = {Meyer, Andreas},
  title     = {Data perspective in business process management},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84806},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 362},
  year      = {2015},
  abstract  = {Gesch{\"a}ftsprozessmanagement ist ein strukturierter Ansatz zur Modellierung, Analyse, Steuerung und Ausf{\"u}hrung von Gesch{\"a}ftsprozessen, um Gesch{\"a}ftsziele zu erreichen. Es st{\"u}tzt sich dabei auf konzeptionelle Modelle, von denen Prozessmodelle am weitesten verbreitet sind. Prozessmodelle beschreiben wer welche Aufgabe auszuf{\"u}hren hat, um das Gesch{\"a}ftsziel zu erreichen, und welche Informationen daf{\"u}r ben{\"o}tigt werden. Damit beinhalten Prozessmodelle Informationen {\"u}ber den Kontrollfluss, die Zuweisung von Verantwortlichkeiten, den Datenfluss und Informationssysteme. Die Automatisierung von Gesch{\"a}ftsprozessen erh{\"o}ht die Effizienz der Arbeitserledigung und wird durch Process Engines unterst{\"u}tzt. Daf{\"u}r werden jedoch Informationen {\"u}ber den Kontrollfluss, die Zuweisung von Verantwortlichkeiten f{\"u}r Aufgaben und den Datenfluss ben{\"o}tigt. W{\"a}hrend aktuelle Process Engines die ersten beiden Informationen weitgehend automatisiert verarbeiten k{\"o}nnen, m{\"u}ssen Daten manuell implementiert und gewartet werden. Dem entgegen verspricht ein modell-getriebenes Behandeln von Daten eine vereinfachte Implementation in der Process Engine und verringert gleichzeitig die Fehleranf{\"a}lligkeit dank einer graphischen Visualisierung und reduziert den Entwicklungsaufwand durch Codegenerierung. Die vorliegende Dissertation besch{\"a}ftigt sich mit der Modellierung, der Analyse und der Ausf{\"u}hrung von Daten in Gesch{\"a}ftsprozessen. Als formale Basis f{\"u}r die Prozessausf{\"u}hrung wird ein konzeptuelles Framework f{\"u}r die Integration von Prozessen und Daten eingef{\"u}hrt. Dieses Framework wird durch operationelle Semantik erg{\"a}nzt, die mittels einem um Daten erweiterten Petrinetz-Mapping vorgestellt wird. Die modellgetriebene Ausf{\"u}hrung von Daten muss komplexe Datenabh{\"a}ngigkeiten, Prozessdaten und den Datenaustausch ber{\"u}cksichtigen. Letzterer tritt bei der Kommunikation zwischen mehreren Prozessteilnehmern auf. Diese Arbeit nutzt Konzepte aus dem Bereich der Datenbanken und {\"u}berf{\"u}hrt diese ins Gesch{\"a}ftsprozessmanagement, um Datenoperationen zu unterscheiden, um Abh{\"a}ngigkeiten zwischen Datenobjekten des gleichen und verschiedenen Typs zu spezifizieren, um modellierte Datenknoten sowie empfangene Nachrichten zur richtigen laufenden Prozessinstanz zu korrelieren und um Nachrichten f{\"u}r die Prozess{\"u}bergreifende Kommunikation zu generieren. Der entsprechende Ansatz ist nicht auf eine bestimmte Prozessbeschreibungssprache begrenzt und wurde prototypisch implementiert. Die Automatisierung der Datenbehandlung in Gesch{\"a}ftsprozessen erfordert entsprechend annotierte und korrekte Prozessmodelle. Als Unterst{\"u}tzung zur Datenannotierung f{\"u}hrt diese Arbeit einen Algorithmus ein, welcher Informationen {\"u}ber Datenknoten, deren Zust{\"a}nde und Datenabh{\"a}ngigkeiten aus Kontrollflussinformationen extrahiert und die Prozessmodelle entsprechend annotiert. Allerdings k{\"o}nnen gew{\"o}hnlich nicht alle erforderlichen Informationen aus Kontrollflussinformationen extrahiert werden, da detaillierte Angaben {\"u}ber m{\"o}gliche Datenmanipulationen fehlen. Deshalb sind weitere Prozessmodellverfeinerungen notwendig. Basierend auf einer Menge von Objektlebenszyklen kann ein Prozessmodell derart verfeinert werden, dass die in den Objektlebenszyklen spezifizierten Datenmanipulationen automatisiert in ein Prozessmodell {\"u}berf{\"u}hrt werden k{\"o}nnen. Prozessmodelle stellen eine Abstraktion dar. Somit fokussieren sie auf verschiedene Teilbereiche und stellen diese im Detail dar. Solche Detailbereiche sind beispielsweise die Kontrollflusssicht und die Datenflusssicht, welche oft durch Aktivit{\"a}ts-zentrierte beziehungsweise Objekt-zentrierte Prozessmodelle abgebildet werden. In der vorliegenden Arbeit werden Algorithmen zur Transformation zwischen diesen Sichten beschrieben. Zur Sicherstellung der Modellkorrektheit wird das Konzept der „weak conformance" zur {\"U}berpr{\"u}fung der Konsistenz zwischen Objektlebenszyklen und dem Prozessmodell eingef{\"u}hrt. Dabei darf das Prozessmodell nur Datenmanipulationen enthalten, die auch in einem Objektlebenszyklus spezifiziert sind. Die Korrektheit wird mittels Soundness-{\"U}berpr{\"u}fung einer hybriden Darstellung ermittelt, so dass Kontrollfluss- und Datenkorrektheit integriert {\"u}berpr{\"u}ft werden. Um eine korrekte Ausf{\"u}hrung des Prozessmodells zu gew{\"a}hrleisten, m{\"u}ssen gefundene Inkonsistenzen korrigiert werden. Daf{\"u}r werden f{\"u}r jede Inkonsistenz alternative Vorschl{\"a}ge zur Modelladaption identifiziert und vorgeschlagen. Zusammengefasst, unter Einsatz der Ergebnisse dieser Dissertation k{\"o}nnen Gesch{\"a}ftsprozesse modellgetrieben ausgef{\"u}hrt werden unter Ber{\"u}cksichtigung sowohl von Daten als auch den zuvor bereits unterst{\"u}tzten Perspektiven bez{\"u}glich Kontrollfluss und Verantwortlichkeiten. Dabei wird die Modellerstellung teilweise mit automatisierten Algorithmen unterst{\"u}tzt und die Modellkonsistenz durch Datenkorrektheits{\"u}berpr{\"u}fungen gew{\"a}hrleistet.},
  language  = {en}
}
@phdthesis{Wettstein2015,
  author    = {Wettstein, Christoph},
  title     = {Cytochrome c-DNA and cytochrome c-enzyme interactions for the construction of analytical signal chains},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-78367},
  school      = {Universit{\"a}t Potsdam},
  pages     = {120},
  year      = {2015},
  abstract  = {Electron transfer (ET) reactions play a crucial role in the metabolic pathways of all organisms. In biotechnological approaches, the redox properties of the protein cytochrome c (cyt c), which acts as an electron shuttle in the respiratory chain, was utilized to engineer ET chains on electrode surfaces. With the help of the biopolymer DNA, the redox protein assembles into electro active multilayer (ML) systems, providing a biocompatible matrix for the entrapment of proteins. In this study the characteristics of the cyt c and DNA interaction were defined on the molecular level for the first time and the binding sites of DNA on cyt c were identified. Persistent cyt c/DNA complexes were formed in solution under the assembly conditions of ML architectures, i.e. pH 5.0 and low ionic strength. At pH 7.0, no agglomerates were formed, permitting the characterization of the NMR spectroscopy. Using transverse relaxation-optimized spectroscopy (TROSY)-heteronuclear single quantum coherence (HSQC) experiments, DNAs' binding sites on the protein were identified. In particular, negatively charged AA residues, which are known interaction sites in cyt c/protein binding were identified as the main contact points of cyt c and DNA. Moreover, the sophisticated task of arranging proteins on electrode surfaces to create functional ET chains was addressed. Therefore, two different enzyme types, the flavin dependent fructose dehydrogenase (FDH) and the pyrroloquinoline quinone dependent glucose dehydrogenase (PQQ-GDH), were tested as reaction partners of freely diffusing cyt c and cyt c immobilized on electrodes in mono- and MLs. The characterisation of the ET processes was performed by means of electrochemistry and the protein deposition was monitored by microgravimetric measurements. FDH and PQQ-GDH were found to be generally suitable for combination with the cyt c/DNA ML system, since both enzymes interact with cyt c in solution and in the immobilized state. The immobilization of FDH and cyt c was achieved with the enzyme on top of a cyt c monolayer electrode without the help of a polyelectrolyte. Combining FDH with the cyt c/DNA ML system did not succeed, yet. However, the basic conditions for this protein-protein interaction were defined. PQQ-GDH was successfully coupled with the ML system, demonstrating that that the cyt c/DNA ML system provides a suitable interface for enzymes and that the creation of signal chains, based on the idea of co-immobilized proteins is feasible. Future work may be directed to the investigation of cyt c/DNA interaction under the precise conditions of ML assembly. Therefore, solid state NMR or X-ray crystallography may be required. Based on the results of this study, the combination of FDH with the ML system should be addressed. Moreover, alternative types of enzymes may be tested as catalytic component of the ML assembly, aiming on the development of innovative biosensor applications.},
  language  = {en}
}
@phdthesis{Kniepert2015,
  author    = {Kniepert, Juliane},
  title     = {Correlation between dynamic parameters and device performance of organic solar cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {129},
  year      = {2015},
  abstract  = {Organic bulk heterojunction (BHJ) solar cells based on polymer:fullerene blends are a promising alternative for a low-cost solar energy conversion. Despite significant improvements of the power conversion efficiency in recent years, the fundamental working principles of these devices are yet not fully understood. In general, the current output of organic solar cells is determined by the generation of free charge carriers upon light absorption and their transport to the electrodes in competition to the loss of charge carriers due to recombination. The object of this thesis is to provide a comprehensive understanding of the dynamic processes and physical parameters determining the performance. A new approach for analyzing the characteristic current-voltage output was developed comprising the experimental determination of the efficiencies of charge carrier generation, recombination and transport, combined with numerical device simulations. Central issues at the beginning of this work were the influence of an electric field on the free carrier generation process and the contribution of generation, recombination and transport to the current-voltage characteristics. An elegant way to directly measure the field dependence of the free carrier generation is the Time Delayed Collection Field (TDCF) method. In TDCF charge carriers are generated by a short laser pulse and subsequently extracted by a defined rectangular voltage pulse. A new setup was established with an improved time resolution compared to former reports in literature. It was found that charge generation is in general independent of the electric field, in contrast to the current view in literature and opposed to the expectations of the Braun-Onsager model that was commonly used to describe the charge generation process. Even in cases where the charge generation was found to be field-dependend, numerical modelling showed that this field-dependence is in general not capable to account for the voltage dependence of the photocurrent. This highlights the importance of efficient charge extraction in competition to non-geminate recombination, which is the second objective of the thesis. Therefore, two different techniques were combined to characterize the dynamics and efficiency of non-geminate recombination under device-relevant conditions. One new approach is to perform TDCF measurements with increasing delay between generation and extraction of charges. Thus, TDCF was used for the first time to measure charge carrier generation, recombination and transport with the same experimental setup. This excludes experimental errors due to different measurement and preparation conditions and demonstrates the strength of this technique. An analytic model for the description of TDCF transients was developed and revealed the experimental conditions for which reliable results can be obtained. In particular, it turned out that the \$RC\$ time of the setup which is mainly given by the sample geometry has a significant influence on the shape of the transients which has to be considered for correct data analysis. Secondly, a complementary method was applied to characterize charge carrier recombination under steady state bias and illumination, i.e. under realistic operating conditions. This approach relies on the precise determination of the steady state carrier densities established in the active layer. It turned out that current techniques were not sufficient to measure carrier densities with the necessary accuracy. Therefore, a new technique {Bias Assisted Charge Extraction} (BACE) was developed. Here, the charge carriers photogenerated under steady state illumination are extracted by applying a high reverse bias. The accelerated extraction compared to conventional charge extraction minimizes losses through non-geminate recombination and trapping during extraction. By performing numerical device simulations under steady state, conditions were established under which quantitative information on the dynamics can be retrieved from BACE measurements. The applied experimental techniques allowed to sensitively analyse and quantify geminate and non-geminate recombination losses along with charge transport in organic solar cells. A full analysis was exemplarily demonstrated for two prominent polymer-fullerene blends. The model system P3HT:PCBM spincast from chloroform (as prepared) exhibits poor power conversion efficiencies (PCE) on the order of 0.5\%, mainly caused by low fill factors (FF) and currents. It could be shown that the performance of these devices is limited by the hole transport and large bimolecular recombination (BMR) losses, while geminate recombination losses are insignificant. The low polymer crystallinity and poor interconnection between the polymer and fullerene domains leads to a hole mobility of the order of 10^-7 cm^2/Vs which is several orders of magnitude lower than the electron mobility in these devices. The concomitant build up of space charge hinders extraction of both electrons and holes and promotes bimolecular recombination losses. Thermal annealing of P3HT:PCBM blends directly after spin coating improves crystallinity and interconnection of the polymer and the fullerene phase and results in comparatively high electron and hole mobilities in the order of 10^-3 cm^2/Vs and 10^-4 cm^2/Vs, respectively. In addition, a coarsening of the domain sizes leads to a reduction of the BMR by one order of magnitude. High charge carrier mobilities and low recombination losses result in comparatively high FF (>65\%) and short circuit current (J_SC ≈ 10 mA/cm^2). The overall device performance (PCE ≈ 4\%) is only limited by a rather low spectral overlap of absorption and solar emission and a small V_OC, given by the energetics of the P3HT. From this point of view the combination of the low bandgap polymer PTB7 with PCBM is a promising approach. In BHJ solar cells, this polymer leads to a higher V_OC due to optimized energetics with PCBM. However, the J_SC in these (unoptimized) devices is similar to the J_SC in the optimized blend with P3HT and the FF is rather low (≈ 50\%). It turned out that the unoptimized PTB7:PCBM blends suffer from high BMR, a low electron mobility of the order of 10^-5 cm^2/Vs and geminate recombination losses due to field dependent charge carrier generation. The use of the solvent additive DIO optimizes the blend morphology, mainly by suppressing the formation of very large fullerene domains and by forming a more uniform structure of well interconnected donor and acceptor domains of the order of a few nanometers. Our analysis shows that this results in an increase of the electron mobility by about one order of magnitude (3 x 10^-4 cm^2/Vs), while BMR and geminate recombination losses are significantly reduced. In total these effects improve the J_SC (≈ 17 mA/cm^2) and the FF (> 70\%). In 2012 this polymer/fullerene combination resulted in a record PCE for a single junction OSC of 9.2\%. Remarkably, the numerical device simulations revealed that the specific shape of the J-V characteristics depends very sensitively to the variation of not only one, but all dynamic parameters. On the one hand this proves that the experimentally determined parameters, if leading to a good match between simulated and measured J-V curves, are realistic and reliable. On the other hand it also emphasizes the importance to consider all involved dynamic quantities, namely charge carrier generation, geminate and non-geminate recombination as well as electron and hole mobilities. The measurement or investigation of only a subset of these parameters as frequently found in literature will lead to an incomplete picture and possibly to misleading conclusions. Importantly, the comparison of the numerical device simulation employing the measured parameters and the experimental \$J-V\$ characteristics allows to identify loss channels and limitations of OSC. For example, it turned out that inefficient extraction of charge carriers is a criticical limitation factor that is often disobeyed. However, efficient and fast transport of charges becomes more and more important with the development of new low bandgap materials with very high internal quantum efficiencies. Likewise, due to moderate charge carrier mobilities, the active layer thicknesses of current high-performance devices are usually limited to around 100 nm. However, larger layer thicknesses would be more favourable with respect to higher current output and robustness of production. Newly designed donor materials should therefore at best show a high tendency to form crystalline structures, as observed in P3HT, combined with the optimized energetics and quantum efficiency of, for example, PTB7.},
  language  = {en}
}
@phdthesis{Senft2015,
  author    = {Senft, Christoph},
  title     = {Contemporary Indian writing in English between global fiction and transmodern historiography},
  series = {Internationale Forschungen zur allgemeinen und vergleichenden Literaturwissenschaft ; 190},
  journal   = {Internationale Forschungen zur allgemeinen und vergleichenden Literaturwissenschaft ; 190},
  publisher = {Rodopi},
  address   = {Leiden},
  isbn      = {978-90-04-30906-7},
  pages     = {239},
  year      = {2015},
  abstract  = {Christoph Senft provides a set of re-readings of contemporary Indian narrative texts as decolonial and pluralistic approaches to the past and thus offers a comprehensive overview of the subcontinent s literary landscape in the 21st century.},
  language  = {en}
}
@phdthesis{Fuenfgeld2015,
  author    = {F{\"u}nfgeld, Maximilian},
  title     = {Compartmentation of adenine nucleotide metabolism},
  school      = {Universit{\"a}t Potsdam},
  pages     = {113},
  year      = {2015},
  language  = {en}
}
@phdthesis{Boettle2015,
  author    = {B{\"o}ttle, Markus},
  title     = {Coastal floods in view of sea level rise},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91074},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiii, 111},
  year      = {2015},
  abstract  = {The sea level rise induced intensification of coastal floods is a serious threat to many regions in proximity to the ocean. Although severe flood events are rare they can entail enormous damage costs, especially when built-up areas are inundated. Fortunately, the mean sea level advances slowly and there is enough time for society to adapt to the changing environment. Most commonly, this is achieved by the construction or reinforcement of flood defence measures such as dykes or sea walls but also land use and disaster management are widely discussed options. Overall, albeit the projection of sea level rise impacts and the elaboration of adequate response strategies is amongst the most prominent topics in climate impact research, global damage estimates are vague and mostly rely on the same assessment models. The thesis at hand contributes to this issue by presenting a distinctive approach which facilitates large scale assessments as well as the comparability of results across regions. Moreover, we aim to improve the general understanding of the interplay between mean sea level rise, adaptation, and coastal flood damage. Our undertaking is based on two basic building blocks. Firstly, we make use of macroscopic flood-damage functions, i.e. damage functions that provide the total monetary damage within a delineated region (e.g. a city) caused by a flood of certain magnitude. After introducing a systematic methodology for the automatised derivation of such functions, we apply it to a total of 140 European cities and obtain a large set of damage curves utilisable for individual as well as comparative damage assessments. By scrutinising the resulting curves, we are further able to characterise the slope of the damage functions by means of a functional model. The proposed function has in general a sigmoidal shape but exhibits a power law increase for the relevant range of flood levels and we detect an average exponent of 3.4 for the considered cities. This finding represents an essential input for subsequent elaborations on the general interrelations of involved quantities. The second basic element of this work is extreme value theory which is employed to characterise the occurrence of flood events and in conjunction with a damage function provides the probability distribution of the annual damage in the area under study. The resulting approach is highly flexible as it assumes non-stationarity in all relevant parameters and can be easily applied to arbitrary regions, sea level, and adaptation scenarios. For instance, we find a doubling of expected flood damage in the city of Copenhagen for a rise in mean sea levels of only 11 cm. By following more general considerations, we succeed in deducing surprisingly simple functional expressions to describe the damage behaviour in a given region for varying mean sea levels, changing storm intensities, and supposed protection levels. We are thus able to project future flood damage by means of a reduced set of parameters, namely the aforementioned damage function exponent and the extreme value parameters. Similar examinations are carried out to quantify the aleatory uncertainty involved in these projections. In this regard, a decrease of (relative) uncertainty with rising mean sea levels is detected. Beyond that, we demonstrate how potential adaptation measures can be assessed in terms of a Cost-Benefit Analysis. This is exemplified by the Danish case study of Kalundborg, where amortisation times for a planned investment are estimated for several sea level scenarios and discount rates.},
  language  = {en}
}