@phdthesis{Ayguel2015,
  author    = {Ayg{\"u}l, Mesut},
  title     = {Pre-collisional accretion and exhumation along the southern Laurasian active margin, Central Pontides, Turkey},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416769},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxxiv, 206},
  year      = {2015},
  abstract  = {The Central Pontides is an accretionary-type orogenic area within the Alpine-Himalayan orogenic belt characterized by pre-collisional tectonic continental growth. The region comprises Mesozoic subduction-accretionary complexes and an accreted intra-oceanic arc that are sandwiched between the Laurasian active continental margin and Gondwana-derived the K{\i}r{\c{s}}ehir Block. The subduction-accretion complexes mainly consist of an Albian-Turonian accretionary wedge representing the Laurasian active continental margin. To the north, the wedge consists of slate/phyllite and metasandstone intercalation with recrystallized limestone, Na-amphibole-bearing metabasite (PT= 7-12 kbar and 400 ± 70 ºC) and tectonic slices of serpentinite representing accreted distal part of a large Lower Cretaceous submarine turbidite fan deposited on the Laurasian active continental margin that was subsequently accreted and metamorphosed. Raman spectra of carbonaceous material (RSCM) of the metapelitic rocks revealed that the metaflysch sequence consists of metamorphic packets with distinct peak metamorphic temperatures. The majority of the metapelites are low-temperature (ca. 330 °C) slates characterized by lack of differentiation of the graphite (G) and D2 defect bands. They possibly represent offscraped distal turbidites along the toe of the Albian accretionary wedge. The rest are phyllites that are characterized by slightly pronounced G band with D2 defect band occurring on its shoulder. Peak metamorphic temperatures of these phyllites are constrained to 370-385 °C. The phyllites are associated with a strip of incipient blueschist facies metabasites which are found as slivers within the offscraped distal turbidites. They possibly represent underplated continental metasediments together with oceanic crustal basalt along the basal d{\´e}collement. Tectonic emplacement of the underplated rocks into the offscraped distal turbidites was possibly achieved by out-of-sequence thrusting causing tectonic thickening and uplift of the wedge. 40Ar/39Ar phengite ages from the phyllites are ca. 100 Ma, indicating Albian subduction and regional HP metamorphism. The accreted continental metasediments are underlain by HP/LT metamorphic rocks of oceanic origin along an extensional shear zone. The oceanic metamorphic sequence mainly comprises tectonically thickened deep-seated eclogite to blueschist facies metabasites and micaschists. In the studied area, metabasites are epidote-blueschists locally with garnet (PT= 17 ± 1 kbar and 500 ± 40 °C). Lawsonite-blueschists are exposed as blocks along the extensional shear zone (PT= 14 ± 2 kbar and 370-440 °C). They are possibly associated with low shear stress regime of the initial stage of convergence. Close to the shear zone, the footwall micaschists consist of quartz, phengite, paragonite, chlorite, rutile with syn-kinematic albite porphyroblast formed by pervasive shearing during exhumation. These types of micaschists are tourmaline-bearing and their retrograde nature suggests high-fluid flux along shear zones. Peak metamorphic mineral assemblages are partly preserved in the chloritoid-micaschist farther away from the shear zone representing the zero strain domains during exhumation. Three peak metamorphic assemblages are identified and their PT conditions are constrained by pseudosections produced by Theriak-Domino and by Raman spectra of carbonaceous material: 1) garnet-chloritoid-glaucophane with lawsonite pseudomorphs (P= 17.5 ± 1 kbar, T: 390-450 °C) 2) chloritoid with glaucophane pseudomorphs (P= 16-18 kbar, T: 475 ± 40 °C) and 3) relatively high-Mg chloritoid (17\%) with jadeite pseudomorphs (P= 22-25 kbar; T: 440 ± 30 °C) in addition to phengite, paragonite, quartz, chlorite, rutile and apatite. The last mineral assemblage is interpreted as transformation of the chloritoid + glaucophane assemblage to chloritoid + jadeite paragenesis with increasing pressure. Absence of tourmaline suggests that the chloritoid-micaschist did not interact with B-rich fluids during zero strain exhumation. 40Ar/39Ar phengite age of a pervasively sheared footwall micaschist is constrained to 100.6 ± 1.3 Ma and that of a chloritoid-micaschist is constrained to 91.8 ± 1.8 Ma suggesting exhumation during on-going subduction with a southward younging of the basal accretion and the regional metamorphism. To the south, accretionary wedge consists of blueschist and greenschist facies metabasite, marble and volcanogenic metasediment intercalation. 40Ar/39Ar phengite dating reveals that this part of the wedge is of Middle Jurassic age partly overprinted during the Albian. Emplacement of the Middle Jurassic subduction-accretion complexes is possibly associated with obliquity of the Albian convergence. Peak metamorphic assemblages and PT estimates of the deep-seated oceanic metamorphic sequence suggest tectonic stacking within wedge with different depths of burial. Coupling and exhumation of the distinct metamorphic slices are controlled by decompression of the wedge possibly along a retreating slab. Structurally, decompression of the wedge is evident by an extensional shear zone and the footwall micaschists with syn-kinematic albite porphyroblasts. Post-kinematic garnets with increasing grossular content and pseudomorphing minerals within the chloritoid-micaschists also support decompression model without an extra heating. Thickening of subduction-accretionary complexes is attributed to i) significant amount of clastic sediment supply from the overriding continental domain and ii) deep level basal underplating by propagation of the d{\´e}collement along a retreating slab. Underplating by basal d{\´e}collement propagation and subsequent exhumation of the deep-seated subduction-accretion complexes are connected and controlled by slab rollback creating a necessary space for progressive basal accretion along the plate interface and extension of the wedge above for exhumation of the tectonically thickened metamorphic sequences. This might be the most common mechanism of the tectonic thickening and subsequent exhumation of deep-seated HP/LT subduction-accretion complexes. To the south, the Albian-Turonian accretionary wedge structurally overlies a low-grade volcanic arc sequence consisting of low-grade metavolcanic rocks and overlying metasedimentary succession is exposed north of the İzmir-Ankara-Erzincan suture (İAES), separating Laurasia from Gondwana-derived terranes. The metavolcanic rocks mainly consist of basaltic andesite/andesite and mafic cognate xenolith-bearing rhyolite with their pyroclastic equivalents, which are interbedded with recrystallized pelagic limestone and chert. The metavolcanic rocks are stratigraphically overlain by recrystallized micritic limestone with rare volcanogenic metaclastic rocks. Two groups can be identified based on trace and rare earth element characteristics. The first group consists of basaltic andesite/andesite (BA1) and rhyolite with abundant cognate gabbroic xenoliths. It is characterized by relative enrichment of LREE with respect to HREE. The rocks are enriched in fluid mobile LILE, and strongly depleted in Ti and P reflecting fractionation of Fe-Ti oxides and apatite, which are found in the mafic cognate xenoliths. Abundant cognate gabbroic xenoliths and identical trace and rare earth elements compositions suggest that rhyolites and basaltic andesites/andesites (BA1) are cogenetic and felsic rocks were derived from a common mafic parental magma by fractional crystallization and accumulation processes. The second group consists only of basaltic andesites (BA2) with flat REE pattern resembling island arc tholeiites. Although enriched in LILE, this group is not depleted in Ti or P. Geochemistry of the metavolcanic rocks indicates supra-subduction volcanism evidenced by depletion of HFSE and enrichment of LILE. The arc sequence is sandwiched between an Albian-Turonian subduction-accretionary complex representing the Laurasian active margin and an ophiolitic m{\´e}lange. Absence of continent derived detritus in the arc sequence and its tectonic setting in a wide Cretaceous accretionary complex suggest that the K{\"o}sdağ Arc was intra-oceanic. This is in accordance with basaltic andesites (BA2) with island arc tholeiite REE pattern. Zircons from two metarhyolite samples give Late Cretaceous (93.8 ± 1.9 and 94.4 ± 1.9 Ma) U/Pb ages. Low-grade regional metamorphism of the intra-oceanic arc sequence is constrained 69.9 ± 0.4 Ma by 40Ar/39Ar dating on metamorphic muscovite from a metarhyolite indicating that the arc sequence became part of a wide Tethyan Cretaceous accretionary complex by the latest Cretaceous. The youngest 40Ar/39Ar phengite age from the overlying subduction-accretion complexes is 92 Ma confirming southward younging of an accretionary-type orogenic belt. Hence, the arc sequence represents an intra-oceanic paleo-arc that formed above the sinking Tethyan slab and finally accreted to Laurasian active continental margin. Abrupt non-collisional termination of arc volcanism was possibly associated with southward migration of the arc volcanism similar to the Izu-Bonin-Mariana arc system. The intra-oceanic K{\"o}sdağ Arc is coeval with the obducted supra-subduction ophiolites in NW Turkey suggesting that it represents part of the presumed but missing incipient intra-oceanic arc associated with the generation of the regional supra-subduction ophiolites. Remnants of a Late Cretaceous intra-oceanic paleo-arc and supra-subduction ophiolites can be traced eastward within the Alp-Himalayan orogenic belt. This reveals that Late Cretaceous intra-oceanic subduction occurred as connected event above the sinking Tethyan slab. It resulted as arc accretion to Laurasian active margin and supra-subduction ophiolite obduction on Gondwana-derived terranes.},
  language  = {en}
}
@phdthesis{Partosch2015,
  author    = {Partosch, Falko},
  title     = {Computergest{\"u}tzte Analysen in der Toxikologie},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82334},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 131, ix},
  year      = {2015},
  abstract  = {Im Rahmen der EU-weiten REACH-Verordnung haben Alternativmethoden zum Tierversuch in der Toxikologie an Bedeutung gewonnen. Die Alternativmethoden gliedern sich auf in In-vitro- und In-silico-Methoden. In dieser Dissertation wurden verschiedene Konzepte der In-silico-Toxikologie behandelt. Die bearbeiteten Themen reichen von quantitativen Strukturaktivit{\"a}tsbeziehungen (QSAR) {\"u}ber eine neue Herangehensweise an das g{\"a}ngige Konzept zur Festlegung von Grenzwerten bis hin zu computerbasierten Modellierungen zum Alkohol- und Bisphenol-A-Stoffwechsel. Das Kapitel {\"u}ber QSAR befasst sich im Wesentlichen mit der Erstellung und Analyse einer Datenbank mit 878 Substanzen, die sich aus Tierversuchsstudien aus dem Archiv des Bundesinstituts f{\"u}r Risikobewertung zusammensetzt. Das Design wurde dabei an eine bereits bestehende Datenbank angepasst, um so einen m{\"o}glichst großen Datenpool zu generieren. In der Analyse konnte u.a. gezeigt werden, dass Stoffe mit niedrigerem Molekulargewicht ein erh{\"o}htes Potential f{\"u}r toxikologische Sch{\"a}den aufwiesen als gr{\"o}ßere Molek{\"u}le. Mit Hilfe des sogenannten TTC-Konzepts k{\"o}nnen Grenzwerte f{\"u}r Stoffe geringer Exposition festgelegt werden, zu denen keine toxikologischen Daten zur Verf{\"u}gung stehen. In dieser Arbeit wurden f{\"u}r die Stoffe dreier Datenbanken entsprechende Grenzwerte festgelegt. Es erfolgte zun{\"a}chst eine g{\"a}ngige strukturbasierte Aufteilung der Substanzen in die Kategorien "nicht toxisch", "m{\"o}glicherweise toxisch" und "eindeutig toxisch". Substanzen, die aufgrund ihrer Struktur in eine der drei Klassen eingeordnet werden, erhalten den entsprechenden Grenzwert. Da in die dritte Klasse auch Stoffe eingeordnet werden, deren Toxizit{\"a}t nicht bestimmbar ist, ist sie sehr groß. Daher wurden in dieser Arbeit die ersten beiden Klassen zusammengelgt, um einen gr{\"o}ßeren Datenpool zu erm{\"o}glichen. Eine weitere Neuerung umfasst die Erstellung eines internen Grenzwerts. Diese Vorgehensweise hat den Vorteil, dass der Expositionsweg herausgerechnet wird und somit beispielsweise Studien mit oraler Verabreichung mit Studien dermaler Verabreichung verglichen werden k{\"o}nnen. Mittels physiologisch basiertem kinetischem Modelling ist es m{\"o}glich, Vorg{\"a}nge im menschlichen K{\"o}rper mit Hilfe spezieller Software nachzuvollziehen. Durch diese Vorgehensweise k{\"o}nnen Expositionen von Chemikalien simuliert werden. In einem Teil der Arbeit wurden Alkoholexpositionen von gestillten Neugeborenen simuliert, deren M{\"u}tter unmittelbar zuvor alkoholische Getr{\"a}nke konsumiert hatten. Mit dem Modell konnte gezeigt werden, dass die Expositionen des Kindes durchweg gering waren. Nach einem Glas Wein wurden Spitzenkonzentrationen im Blut von Neugeborenen von 0,0034 Promille ermittelt. Zum Vergleich wurde die Exposition durch ein f{\"u}r S{\"a}uglinge zugelassenes alkoholhaltiges pflanzliches Arzneimittel simuliert. Hier wurden Spitzenkonzentrationen von 0,0141 Promille erreicht. Daher scheinen Empfehlungen wie gelegentlicher Konsum ohne sch{\"a}digende Wirkung auf das Kind wissenschaftlich fundiert zu sein. Ein weiteres Kinetik-Modell befasste sich mit dem Stoffwechsel von Bisphenol A. Teils widerspr{\"u}chliche Daten zur Belastung mit BPA in der wissenschaftlichen Literatur f{\"u}hren wiederholt zu Anregungen, den Grenzwert der Chemikalie anzupassen. Die Funktionalit{\"a}t der am Metabolismus beteiligten Enzyme kann je nach Individuum unterschiedlich ausgepr{\"a}gt sein. Mittels Modellings konnte hier gezeigt werden, dass dies maßgeblich dazu f{\"u}hrt, dass sich berechnete Plasmaspiegel von Individuen bis zu 4,7-fach unterscheiden. Die Arbeit konnte somit einen Beitrag zur Nutzung und Weiterentwicklung von In-silico-Modellen f{\"u}r diverse toxikologische Fragestellungen leisten.},
  language  = {de}
}
@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{TabaresJimenez2015,
  author    = {Tabares Jim{\´e}nez, Adri{\´a}n de Jes{\´u}s},
  title     = {Palabras de fundadores, forasteros y cachacos},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85630},
  school      = {Universit{\"a}t Potsdam},
  pages     = {227},
  year      = {2015},
  abstract  = {Die vorliegende Dissertation analysiert die Mentalit{\"a}ten der b{\"u}rgerlichen Bewohner Bogotas 19. Jahrhundert. Einblicke in die Fremd- und Eigenperspektiven der Bogotaner werden durch die Analyse von Reiseliteratur gewonnen. Methodologisch st{\"u}tzt sich die Arbeit auf den Vergleich zwischen europ{\"a}ischen Reiseberichten aus dem 19. Jh., Chroniken aus dem 16. Jh. sowie zwei kolumbianische Romane aus dem fr{\"u}hen 20.. Jh. Die Texte werden historiographisch behandelt; obwohl sie unterschiedlichen literarischen Genres angeh{\"o}ren, weisen sie einen gemeinsamen autobiographischen Charakter auf. Aus den Erfahrungen und Gedanken der Reisenden werden v.a. die Auswirkungen der geographischen und sozialen Isolation thematisiert, sowie die Einfl{\"u}sse von politischen und religi{\"o}sen Diskursen auf die Bildung von b{\"u}rgerlichem Gedankengut.},
  language  = {es}
}
@phdthesis{Ucar2015,
  author    = {U{\c{c}}ar, Magdalena},
  title     = {Zeugenschaft im Bild},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-406087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {145},
  year      = {2015},
  abstract  = {Zentrales Anliegen der Dissertation ist, Zeugenschaft als visuelle Strategie zu beleuchten. In Abgrenzung zur These der Undarstellbarkeit der Shoah wird der Begriff der Sichtbarmachung nutzbar gemacht, um Prozesse und die Wirkung von Bildern im Zusammenhang mit Zeugenschaft herauszustellen. Ausgangspunkt dabei ist, dass bildliche Zeugnisse einen Gegenpol zu den standardisierten Visualisierungspraktiken der Shoah bieten, sprich dem historischen Bildmaterial aufgenommen durch die Alliierten und der Nationalsozialisten. In der Arbeit wird das historische Bildmaterial als Visualisierungspraxis problematisiert und visuellen Zeugnissen gegen{\"u}bergestellt, die Augen- und {\"U}berlebenszeugen der Shoah, aber auch authentische Orte des Geschehens aus einer nachtr{\"a}glichen Perspektive zeigen. Dabei werden insbesondere zwei kritische Strategien des Umgangs mit historischen Bildern der Shoah hervorgehoben: das Hinterfragen von Archivbildern innerhalb des Films (Harun Farockis AUFSCHUB, 2007) und die Verweigerung von Archivbildern aus der Zeit des Zweiten Weltkrieges (Claude Lanzmanns SHOAH, 1985). Seit den 1990er Jahren wird Zeugenschaft in der Forschung als philosophische, moralische und erkenntnistheoretische Kategorie in den USA, aber auch in Deutschland viel diskutiert. Dabei wurde die bild- und medienwissenschaftliche Perspektive im Zusammenhang mit Zeugenschaft kaum beleuchtet, darin liegt der Forschungsbeitrag der Arbeit. Insbesondere drei Gesichtspunkte von visueller Zeugenschaft werden herausgearbeitet: 1) die Sichtbarmachung der {\"U}berlebenden und der Orte des Geschehens im Jetzt, 2) die nichtsprachlichen Aspekte von Zeugenaussagen und 3) die Rolle des Zuschauers, der durch den Akt des Sehens in einem Imaginationsprozess eine Verkn{\"u}pfung zwischen den Bildern aus der Jetztzeit und der nicht-sichtbaren Vergangenheit herstellt. Polen nimmt eine besondere historische Rolle als Zentrum des europ{\"a}ischen Judentums bis zum Zweiten Weltkrieg und gleichzeitig als »Schauplatz des Holocaust« und Ort der Augenzeugenschaft ein. Maßgeblich hat Claude Lanzmanns Film SHOAH dazu beigetragen, die Konzentrations- und Vernichtungslager im Polen der Nachkriegszeit sichtbar zu machen, und damit nicht nur Generationen von polnischen Filmemachern und K{\"u}nstlern nach ihm beeinflusst, sondern auch kontroverse Debatten in Polen ausgel{\"o}st. Anhand der ausgew{\"a}hlten Filme l{\"a}sst sich in der polnischen Erinnerungskultur seit der Wende von 1989 eine Hinwendung zur polnisch-j{\"u}dischen Geschichte erkennen, die sich verst{\"a}rkt mit den Fragen der polnischen Mitt{\"a}terschaft und Schuld an der Shoah auseinandersetzt. Der Untersuchungsgegenstand unterteilt sich in zwei Formate: Dokumentar- und Kunstfilm. Einerseits ist das auf ihre unterschiedlichen Produktions- und Rezeptionsbedingungen sowie die L{\"a}nge der Arbeiten zur{\"u}ckzuf{\"u}hren. Andererseits bewegen sich die Kategorien auf verschiedenen Reflexionsebenen und zielen auf unterschiedliche Wirkungen beim Zuschauer ab. W{\"a}hrend sich in den Dokumentarfilmen zum Teil explizite Bez{\"u}ge (aber auch Abgrenzungen) zum Lanzmann'schen Projekt erkennen lassen, handelt es sich bei den Produktionen des zeitgen{\"o}ssischen K{\"u}nstlers Artur Żmijewski um einen Meta-Diskurs, der auf radikale und provokative Art und Weise bestehende erinnerungskulturelle Praktiken ausstellt und kritisch hinterfragt.},
  language  = {de}
}
@phdthesis{Helpa2015,
  author    = {Helpa, Vanessa},
  title     = {Interplay between mineral reaction and deformation via structural defects},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90332},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 104},
  year      = {2015},
  abstract  = {This thesis contains three experimental studies addressing the interplay between deformation and the mineral reaction between natural calcite and magnesite. The solid-solid mineral reaction between the two carbonates causes the formation of a magnesio-calcite precursor layer and a dolomite reaction rim in every experiment at isostatic annealing and deformation conditions. CHAPTER 1 briefly introduces general aspects concerning mineral reactions in nature and diffusion pathways for mass transport. Moreover, results of previous laboratory studies on the influence of deformation on mineral reactions are summarized. In addition, the main goals of this study are pointed out. In CHAPTER 2, the reaction between calcite and magnesite single crystals is examined at isostatic annealing conditions. Time series performed at a fixed temperature revealed a diffusion-controlled dolomite rim growth. Two microstructural domains could be identified characterized by palisade-shaped dolomite grains growing into the magnesite and granular dolomite growing towards calcite. A model was provided for the dolomite rim growth based on the counter-diffusion of CaO and MgO. All reaction products exhibited a characteristic crystallographic relationship with respect to the calcite reactant. Moreover, kinetic parameters of the mineral reaction were determined out of a temperature series at a fixed time. The main goal of the isostatic test series was to gain information about the microstructure evolution, kinetic parameters, chemical composition and texture development of the reaction products. The results were used as a reference to quantify the influence of deformation on the mineral reaction. CHAPTER 3 deals with the influence of non-isostatic deformation on dolomite and magnesio-calcite layer production between calcite and magnesite single crystals. Deformation was achieved by triaxial compression and by torsion. Triaxial compression up to 38 MPa axial stress at a fixed time showed no significant influence of stress and strain on dolomite formation. Time series conducted at a fixed stress yield no change in growth rates for dolomite and magnesio-calcite at low strains. Slightly larger magnesio-calcite growth rates were observed at strains above >0.1. High strains at similar stresses were caused by the activation of additional glide systems in the calcite single crystal and more mobile dislocations in the magnesio-calcite grains, providing fast diffusion pathways. In torsion experiments a gradual decrease in dolomite and magnesio-calcite layer thickness was observed at a critical shear strain. During deformation, crystallographic orientations of reaction products rearranged with respect to the external framework. A direct effect of the mineral reaction on deformation could not be recognized due to the relatively small reaction product widths. In CHAPTER 4, the influence of starting material microfabrics and the presence of water on the reaction kinetics was evaluated. In these experimental series polycrystalline material was in contact with single crystals or two polycrystalline materials were used as reactants. Isostatic annealing resulted in different dolomite and magnesio-calcite layer thicknesses, depending on starting material microfabrics. The reaction progress at the magnesite interface was faster with smaller magnesite grain size, because grain boundaries provided fast pathways for diffusion and multiple nucleation sites for dolomite formation. Deformation by triaxial compression and torsion yield lower dolomite rim thicknesses compared to annealed samples for the same time. This was caused by grain coarsening of polycrystalline magnesite during deformation. In contrast, magnesio-calcite layers tended to be larger during deformation, which triggered enhanced diffusion along grain boundaries. The presence of excess water had no significant influence on the reaction kinetics, at least if the reactants were single crystals. In CHAPTER 5 general conclusions about the interplay between deformation and the mineral reaction in the carbonate system are presented. Finally, CHAPTER 6 highlights possible future work in the carbonate system based on the results of this study.},
  language  = {en}
}
@phdthesis{Streich2015,
  author    = {Streich, David},
  title     = {Understanding massive disk galaxy formation through resolved stellar populations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81027},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 140},
  year      = {2015},
  abstract  = {In this thesis we utilize resolved stellar populations to improve our understanding of galaxy formation and evolution. In the first part we improve a method for metallicity determination of faint old stellar systems, in the second and third part we analyze the individual history of six nearby disk galaxies outside the Local Group. A New Calibration of the Color Metallicity Relation of Red Giants for HST data: It is well known, that the color distribution of stars on the the Red Giant Branch (RGB) can be used to determine metallicities of old stellar populations that have only shallow photometry. Based on the largest sample of globular clusters ever used for such studies, we quantify the relation between metallicity and color in the widely used HST ACS filters F606W and F814W. We use a sample of globular clusters from the ACS Globular Cluster Survey and measure their RGB color at given absolute magnitudes to derive the color-metallicity relation. We find a clear relation between metallicity and RGB color; we investigate the scatter and the uncertainties in this relation and show its limitations. A comparison with isochrones shows reasonably good agreement with BaSTI models, a small offset to Dartmouth models, and a larger offset to Padua models. Even for the best globular cluster data available, the metallicity of a simple stellar population can be determined from the RGB alone only with an accuracy of 0.3 dex for [M/H]<-1, and 0.15 dex for [M/H]>-1. For mixed populations, as they are observed in external galaxies, the uncertainties will be even larger due to uncertainties in extinction, age, etc. Therefore caution is necessary when interpreting photometric metallicities. The Structural History of Nearby Low Mass Disk Galaxies: We study the individual evolution histories of three nearby, low-mass, edge-on galaxies (IC5052, NGC4244, NGC5023). Using the color magnitude diagrams of resolved stellar populations, we construct star count density maps for populations of different ages and analyze the change of structural parameters with stellar age within each galaxy. The three galaxies show low vertical heating rates, which are much lower than the heating rate of the Milky Way. This indicates that heating agents, as giant molecular clouds and spiral structure are weak in low mass galaxies. We do not detect a separate thick disk in any of the three galaxies, even though our observations cover a larger range in equivalent surface brightness than any integrated light study. While scaleheights increase with age, each population can be well described by a single disk. Only two of the galaxies contain a very weak additional component, which we identify as the faint halo. The mass of these faint halos is less than 1\% of the mass of the disk. All populations in the three galaxies exhibit no or only little flaring. While this finding is consistent with previous integrated light studies, it poses strong constraints on galaxy formation models, because most theoretical simulations often find strong flaring due to interactions or radial migration. Furthermore, we find breaks in the radial profiles of all three galaxies. The radii of these breaks are independent of age, and the break strength is decreasing with age in two of the galaxies (NGC4244 and NGC5023). This is consistent with break formation models, that combine a star formation cutoff with radial migration. The differing behavior of IC5052 can be explained by a recent interaction or minor merger. The Structural History of Massive Disk Galaxies: We extend the structural analysis of stellar populations with distinct ages to three massive galaxies, NGC891, NGC4565 and NGC7814. While confusion effects due to the high stellar number densities in their central region, and the prominent dust lanes inhibit an detailed analysis of the radial profiles, we can study their vertical structure. These massive galaxies also have a slower heating than the Milky Way, comparable to the low mass galaxies. This can be traced back to their already thick young populations and thick layers of their interstellar medium. We do not find a clear separate thick disk in any of these three galaxies; all populations can be described by a single disk plus a S\'ersic bulge/halo component. In contrast to the low mass galaxies, we cannot rule out the presence of thick disks in the massive galaxies, because of the strong influence of the halo, that might hide the possible contribution of the thick disk to the vertical star count profiles. However, the faintness of the possible thick disks still points to problems in the earlier ubiquitous findings of thick disks in external galaxies.},
  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{Fettkenhauer2015,
  author    = {Fettkenhauer, Christian},
  title     = {Ionothermale Synthese funktioneller Kohlenstoffnitrid basierter Materialien},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-78087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 123},
  year      = {2015},
  abstract  = {Die Doktorarbeit behandelt die Synthese Kohlenstoffnitrid basierter Materialien in eutektischen Mischungen bivalenter Metallchloride. Der Fokus liegt dabei auf ZnCl2-, SnCl2- und CoCl2-haltigen eutektischen Mischungen, in denen die Kondensation gebr{\"a}uchlicher organischer Precursoren durchgef{\"u}hrt wird. Im Rahmen dessen wird untersucht wie durch die Reaktionsf{\"u}hrung in Salzschmelzen unterschiedlicher Lewis-Acidit{\"a}t, neben der Molek{\"u}lstruktur andere charakteristische Eigenschaften, wie Morphologie, Kristallinit{\"a}t und spezifische Oberfl{\"a}chen, der Materialien kontrolliert werden k{\"o}nnen. Dar{\"u}ber hinaus werden die optischen Eigenschaften der Materialien er{\"o}rtert und in diesem Zusammenhang die Eignung als Photokatalysatoren f{\"u}r den oxidativen Abbau organischer Farbstoffe und f{\"u}r die photokatalytische Wasserreduktion bzw. -oxidation untersucht. Zus{\"a}tzlich wird gezeigt, wie im System LiCl/KCl in einem einstufigen Prozess edelmetallfreie Kohlenstoffnitrid Komposite zur photokatalytischen Wasserreduktion hergestellt werden k{\"o}nnen.},
  language  = {de}
}
@phdthesis{Grygiel2015,
  author    = {Grygiel, Konrad},
  title     = {Poly(ionic liquid) stabilizers and new synthetic approaches},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80367},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 126},
  year      = {2015},
  abstract  = {The main focus of the present thesis was to investigate the stabilization ability of poly(ionic liquid)s (PILs) in several examples as well as develop novel chemical structures and synthetic routes of PILs. The performed research can be specifically divided into three parts that include synthesis and application of hybrid material composed of PIL and cellulose nanofibers (CNFs), thiazolium-containing PILs, and main-chain imidazolium-type PILs. In the first chapter, a vinylimidazolium-type IL was polymerized in water in the presence of CNFs resulting in the in situ electrostatic grafting of polymeric chains onto the surface of CNFs. The synthesized hybrid material merged advantages of its two components, that is, superior mechanical strength of CNFs and anion dependent solution properties of PILs. In contrast to unmodified CNFs, the hybrid could be stabilized and processed in organic solvents enabling its application as reinforcing agent for porous polyelectrolyte membranes. In the second part, PILs and ionic polymers containing two types of thiazolium repeating units were synthesized. Such polymers displayed counterion dependent thermal stability and solubility in organic solvents of various dielectric constants. This new class of PILs was tested as stabilizers and phase transfer agents for carbon nanotubes in aqueous and organic media, and as binder materials to disperse electroactive powders and carbon additives in solid electrode in lithium-ion batteries. The incorporation of S and N atoms into the polymeric structures make such PILs also potential precursors for S, N - co-doped carbons. In the last chapter, reactants originating from biomass were successfully harnessed to synthesize main-chain imidazolium-type PILs. An imidazolium-type diester IL obtained via a modified Debus-Radziszewski reaction underwent transesterification with diol in a polycondensation reaction. This yielded a polyester-type PIL which CO2 sorption properties were investigated. In the next step, the modified Debus-Radziszewski reaction was further applied to synthesize main-chain PILs according to a convenient, one-step protocol, using water as a green solvent and simple organic molecules as reagents. Depending on the structure of the employed diamine, the synthesized PILs after anion exchange showed superior thermal stability with unusually high carbonization yields. Overall, the outcome of these studies will actively contribute to the current research on PILs by introducing novel PIL chemical structures, improved synthetic routes, and new examples of stabilized materials. The synthesis of main-chain imidazolium-type PILs by a modified Debus-Radziszewski reaction is of a special interest for the future work on porous ionic liquid networks as well as colloidal PIL nanoparticles.},
  language  = {en}
}