Mathematical analysis, scaling and simulation of flow and transport during immiscible two-phase flow

Fluid flow and transport in fractured geological formations is of fundamental socio-economic importance, with applications ranging from oil recovery from the largest remaining hydrocarbon reserves to bioremediation techniques. Two mechanisms are particularly relevant for flow and transport, namely spontaneous imbibition (SI) and hydrodynamic dispersion. This thesis investigates the influence of SI and dispersion on flow and transport during immiscible two-phase flow. We make four main contributions. Firstly, we derive general, exact analytic solutions for SI that are valid for arbitrary petrophysical properties. This should finalize the decades-long search for analytical solutions for SI. Secondly, we derive the first non-dimensional time for SI that incorporates the influence of all parameters present in the two-phase Darcy formulation - a problem that was open for more than 90 years. Thirdly, we show how the growth of the dispersive zone depends on the flow regime and on adsorption. To that end we derive the first known set of analytical solutions for transport that fully accounts for the effects of capillarity, viscous forces and dispersion. Finally, we provide numerical tools to investigate the influence of heterogeneity by extending the higher order finite-element finite-volume method on unstructured grids to the case of transport and two-phase flow

An Open Model for Researching the Role of Culture in Online Self-Disclosure

The analysis of consumers’ personal information (PI) is a significant source to learn about consumers. In online settings, many consumers disclose PI abundantly - this is particularly true for information provided on social network services. Still, people manage the privacy level they want to maintain by disclosing by disclosing PI accordingly. In addition, studies have shown that consumers’ online self-disclosure (OSD) differs across cultures. Therefore, intelligent systems should consider cultural issues when collecting, processing, storing or protecting data from consumers. However, existing studies typically rely on a comparison of two cultures, providing valuable insights but not drawing a comprehensive picture. We introduce an open research model for cultural OSD research, based on the privacy calculus theory. Our open research model incorporates six cultural dimensions, six predictors, and 24 structured propositions. It represents a comprehensive approach that provides a basis to explain possible cultural OSD phenomena in a systematic way

Akkulturation türkischer Jugendlicher im Raum Wien

Der Umgang mit Migration und das Zusammenleben in kultureller Vielfalt spielen heute eine zentrale Rolle im Rahmen unterschiedlichster sozialpolitischer Fragestellungen. In vielen Ländern verläuft der Prozess der Akkulturation für ImmigrantInnen sowie für die Gesellschaft des Aufnahmelandes unproblematisch. In Österreich kommt es gerade in letzte Zeit immer häufiger zu Problemen in Bezug auf die Integration von ImmigrantInnen. Studien zeigten, dass ImmigrantInnen unterschiedliche Wege im Prozess der Akkulturation einschlagen und abhängig von ihrer ethnokulturellen Herkunft und der Gesellschaft des Aufnahmelandes unterschiedliche Anpassungsmuster resultieren. Die vorliegende Arbeit untersuchte den Akkulturationsprozess von türkischen Jugendlichen im Raum Wien im Rahmen einer Fragebogenuntersuchung. 306 SchülerInnen der 6./7. und 9./10. Schulstufe aus Schulen im Raum Wien wurden nach deren Akkulturationsstrategien, ethnischer (türkischer) Identität, Sprachgebrauch von Deutsch sowie nach deren Sprachfertigkeiten in den beiden Sprachen Deutsch und Türkisch befragt. Im Durchschnitt präferierten die Jugendlichen die Akkulturationsstrategie Integration am meisten, gefolgt von Separation, Assimilierung und Marginalisierung. Knapp über die Hälfte der befragten Jugendlichen wiesen eine stark ausgeprägte ethnische (türkische) Identität auf. Die Jugendlichen gaben an, im Durchschnitt bessere Sprachfertigkeiten in Deutsch als in Türkisch zu haben, der Sprachgebrauch von Deutsch zuhause und mit Freunden wurde als eher moderat eingestuft. Altersabhängigkeiten wurden für die Akkulturationsstrategien Marginalisierung und Assimilierung sowie für die Sprachfertigkeiten in Türkisch festgestellt. Geschlechtsspezifische Unterschiede konnten für den Gebrauch der deutschen Sprache zuhause nachgewiesen werden. Mithilfe einer Clusteranalyse wurden Gruppen von Jugendlichen gebildet, die sich in ihrem Akkulturationsmuster ähnlich waren. Es konnten vier verschiedene Akkulturationsmuster gefunden werden. Die größte gefundene Gruppe der „unsicheren Jugendlichen“ zeichnete sich durch Einstellungs- und Verhaltensmuster aus, welche auf Unentschlossenheit bzw. Unsicherheit im Akkulturationsprozess hindeuteten. Die anderen drei Gruppen wurden durch Verhaltens- und Einstellungsmuster charakterisiert, welche entweder stark in Richtung der österreichischen nationalen Kultur, der eigenen türkischen Kultur oder in Richtung eines bikulturellen Miteinanders gingen.Dealing with integration in our society and living together in a multicultural society is a central issue when it comes to socio-political decisions. Quite a view countries, including their host society and the different groups of immigrants, handle the process of immigration very well. However, in Austria problems with immigration are seen quite often. Investigations revealed, that immigrants show distinct ways of acculturation in the process of cultural adaptation and the way of acculturation they chose depends on the ethno cultural group itself and the society of settlement. The present investigation explores the process of acculturation of Turkish immigrant youth in Vienna, Austria using a questionnaire study. 306 students of the 6./7. and 9./10. grade participated in this study. Their acculturations strategies, ethnic identity, language skills in German and Turkish and their German language use at home and with friends were investigated. On average, Turkish youth preferred the acculturation strategy integration most, followed by separation, assimilation and marginalisation. The ethnic (Turkish) identity was well and strong developed for slightly more than 50% of the sample. The Turkish sample showed better language skills in German than in Turkish, however their use of German at home and with friends was moderate. The age of the participants had an effect on the acculturation strategies marginalisation and assimilation and on the self-evaluated Turkish language skills. Sex differences were found for the language use at home. Using cluster analysis, Turkish participants were grouped into clusters, showing similar patterns in the process of acculturation. Four distinct patterns of behaviour and attitudes in the process of acculturation were found. The biggest group, named “unsettled youth” consisted of Turkish adolescents showing uncertain behaviours and attitudes. The other three groups consisted of people showing either very national (Austrian), ethnic (Turkish) or bicultural (Austrian and Turkish) patterns in the process of acculturation

ABOVEGROUND WOODY BIOMASS PRODUCTION OF DIFFERENT TREE SPECIES IN SILVOARABLE AGROFORESTRY SYTEMS WITH ORGANIC AND INTEGRATED CULTIVATION IN SOUTHERN GERMANY

The increasing demand for bioenergy and the combination of agricultural production with conservation has made agroforestry to a sustainable land-management option. Aboveground woody biomass plays a decisive role considering the economic value of the agroforestry systems as well as the carbon storage. With the objective to study aboveground woody biomass production of agroforestry systems with different cultivation methods (organic/ integrated), short rotation plantations of different tree species were established 2009 and coppiced in 2012. The studied tree species were black alder (Alnus glutinosa), black locust (Robinia pseudoacacia), poplar “Max 3”, (Populus maximowiczii x Populus nigra) and willow “Inger” (Salix triandra x Salix viminalis). At the end of each growing season biomass production was estimated by an allometric model that predicted individual tree biomass from stem diameter. At the end of the rotation biomass was estimated directly by harvesting. Biomass production ranged from 3.9 to 10.9 tDM ha-1a-1 with poplar and locust having highest growth rates. Significant variation was observed between tree species, but not between management (organic/ integrated), what indicates that organic and integrated agroforestry systems can have a comparable tree biomass production. Small-scale differences of the soil caused high intraspecific variation and suggest the inclusion of further soil investigations

Outpatient multidisciplinary cancer rehabilitation in Switzerland: a status assessment

Aim This study aimed to assess the situation of outpatient multidisciplinary cancer rehabilitation in Switzerland as of March 2018. Subject and methods Seventeen programmes providing outpatient cancer rehabilitation were identified; 12 in the German-speaking, 4 in the French-speaking and 1 in the Italian-speaking part of Switzerland. Structure, organisation, type of programme and details on therapies offered were assessed. Difference by language regions and the status of the programme (running vs in development) were examined in a descriptive analysis. Results Centres in the German- and Italian-speaking parts had mostly individual modular programmes with a longer duration (median: 12 weeks) and low intensity (median: 2.5–3 h per week). The French-speaking part had standard programmes with a shorter duration (median: 9 weeks) but higher intensity (median: 5.5 h per week) and a higher number of obligatory modules a patient must attend (median: 2 instead of 1). The language regions also showed differences in duration of therapies, communication, indications and screening instruments. Conclusion Outpatient cancer rehabilitation in Switzerland is characterized by a wide range of programmes. These differences between language regions, as well as between the individual programmes, highlight important variables that may influence the efficiency and the quality of the different programmes; understanding these variables could lead to improvements in cancer rehabilitation in Switzerland

Ageing Effects in Mounting Media of Microscope Slide Samples from Natural History Collections: A Case Study with Canada Balsam and PermountTM

Microscope slide collections represent extremely valuable depositories of research material in a natural history, forensic, veterinary, and medical context. Unfortunately, most mounting media of these slides deteriorate over time, with the reason for this not yet understood at all. In this study, Raman spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, and different types of light microscopy were used to investigate the ageing behaviour of naturally aged slides from museum collections and the experimentally aged media of Canada balsam and PermountTM, representing a natural and a synthetic resin, respectively, with both being based on mixtures of various terpenes. Whereas Canada balsam clearly revealed chemical ageing processes, visible as increasing colouration, PermountTM showed physical deterioration recognisable by the increasing number of cracks, which even often impacted a mounted specimen. Noticeable changes to the chemical and physical properties of these mounting media take decades in the case of Canada balsam but just a few years in the case of PermountTM. Our results question whether or not Canada balsam should really be regarded as a mounting medium that lasts for centuries, if its increasing degree of polymerisation can lead to a mount which is no longer restorable.Deutsche ForschungsgemeinschaftPeer Reviewe

Concurrent, Web-First, or Web-Only? How Different Mode Sequences Perform in Recruiting Participants for a Self-Administered Mixed-mode Panel Study

During the COVID-19 pandemic, many survey programs switched to self-administered modes of data collection, often offering respondents both web-based and paper-based questionnaires. However, there is little guidance as to when to offer which mode, especially when the aim is to recruit participants for a panel survey. This study examines the effectiveness of different mode-sequence designs by analyzing an experiment implemented in the recruitment wave of the German panel study "Family Research and Demographic Analysis." We randomly assigned 108,256 individuals aged 18-49 years to one of three mode-sequence-design conditions: concurrent, web-first including a paper-based questionnaire with the second reminder (web-first-2), and web-first including a paper-based questionnaire with the third reminder (web-first-3). A fourth, simulated group did not receive a paper-based questionnaire (web-only). We analyzed how different mode-sequence designs affected outcome rates, sample composition, response distributions, data quality, share of paper-based questionnaires, postage costs, number of postal mailings in the recruitment wave, and participation in the first regular wave. Our results show no differences in response distributions and small differences in sample composition across the four mode-sequence designs. As the web-first-2 and simulated web-only designs yielded comparatively good response and recruitment rates at reasonable costs, we recommend their use when surveying adults between 18 and 49 years old.Während der COVID-19-Pandemie gingen viele Erhebungsprogramme zu selbstverwalteten Formen der Datenerhebung über und boten den Befragten häufig sowohl webbasierte als auch papierbasierte Fragebögen an. Es gibt jedoch kaum Anhaltspunkte dafür, wann welcher Modus angeboten werden sollte, insbesondere wenn das Ziel darin besteht, Teilnehmende für eine Panelerhebung zu rekrutieren. Diese Studie untersucht die Effektivität verschiedener Modus-Sequenz-Designs durch die Analyse eines Experiments, das in der Rekrutierungswelle der deutschen Panelstudie "Familienforschung und Demographische Analyse" durchgeführt wurde