Mathematical modeling of diafiltration

The main objective of this study is to provide a general mathematical model in a compact form for batch diafiltration techniques. The presented mathematical framework gives a rich representation of diafiltration processes due to the employment of concentration-dependent solute rejections. It unifies the existing models for constant volume dilution mode, variable volume dilution mode, and concentration mode operations. The use of such a mathematical framework allows the optimization of the overall diafiltration process. The provided methodology is particularly applicable for decision makers to choose an appropriate diafiltration technique for the given separation design problem

Von der Grounded Theory zur gebauten Theorie: Design Games als soziologische Methode

Spiele sind beliebte Heuristiken soziologischer Theoriebildung. Ihr Potential für die empirische Forschung wurde bislang aber nicht systematisch erkannt und erprobt. Dieses Working Paper handelt vom Versuch, qualitative Grounded Theory Methodologie und Spielgestaltung im Sinne von Design Games zu verbinden. Wir schließen dabei an die neue Strömung der Designsoziologie an, die über disziplinäre Grenzen hinweg Ideen aus dem Mediendesign in den soziologischen Methodenkanon aufnimmt. Das hier vorgestellte Design Game "Windschatten" ist der Prototyp für ein Kooperationsspiel mit spezifischen Erkenntnisansprüchen und trägt zu den Debatten der Designsoziologie bei. In diesem Paper stellen wir die methodische Herstellung des Spiels vor und zeigen, wie Designmethoden mit den Prinzipien qualitativer Sozialforschung verknüpft werden können. Die Strukturelemente von Spielen werden dabei als Möglichkeiten erkannt, im Zuge reflexiver und iterativ ausgerichteter qualitativer Forschung empirisch fundierte Thesen über spezifische Forschungsgegenstände methodisch zu testen, habituelle Wahrnehmungs- und Handlungsmuster zu erheben und zugleich kreative Experimentierräume für die beteiligten Forschungssubjekte zu schaffen. Design Games verbinden damit Aspekte rekonstruierender Analyse und engagierter Aktionsforschung. Dieses Working Paper macht die Verfahren und Prozesse der Spielgestaltung transparent, beschreibt das Wechselspiel zwischen der Spielgestaltung und den etablierten Grounded Theory Verfahren im Forschungsprozess und soll damit andere Forschende zur Weitergestaltung des Design Games anregen. Mit der angehängten Spielanleitung möchten wir zudem dazu anregen, das Spiel "Windschatten" in neue Kontexte und für neue Forschungszwecke zu nutzen. Die Spielanleitung und einige grafische Spieleelemente sind dem Working Paper beigelegt.Games are popular heuristics of sociological theory. However, their potential for empirical research has not yet been systematically recognized and tested. In this working paper, we attempt to combine qualitative grounded theory methodology and game design in the sense of design games. With the rise of digital media as a major sociological topic, scholars also pointed to the methodological potentials of media design for qualitative inquiries. We present the design game "Windschatten" ("slipstream") as a prototype for a cooperative game with specific research interests. By doing so this paper contributes to the debates of design sociology by making transparent how a particular experimental design method can be linked methodologically with qualitative social research. The structural elements of games are introduced as means to empirically test grounded theories about specific research objects in the course of reflexive and iterative qualitative research, to analyze habitual patterns of perception and action, and to create experimental spaces of creativity for the research subjects involved. We argue that design games thereby link analytical qualitative research with democratic and participatory processes of inquiry. The working paper makes the procedures and processes of game design transparent, describes its interplay with established grounded theory procedures in the research process, and thus aims to inspire other researchers to further develop and use the design game "Winschatten"

Dynamic optimization of batch diafiltration processes

A comprehensive modeling approach is proposed for the dynamic simulation and operation optimization of batch diafiltration processes. We provide a unified technology for water utilization control that addresses generality ver- sus special cases. A rigorous dynamical model of the diafiltration process with concentration-dependent rejections of solutes is developed. We deter- mine the optimal time-dependent profile of the diluant flow for the entire process using dynamic optimization methods. The results show that optimal process operation needs not to be any of the conventional diafiltration con- cepts. The presented optimization technique is a useful tool for improving the performance of a membrane diafiltration process

Enhancing optimization planning models for health human resources management with foresight

Achieving a balanced healthcare workforce requires health planners to adjust the supply of health human resources (HHR). Mathematical programming models have been widely used to assist such planning, but the way uncertainty is usually considered in these models entails methodological and practical issues and often disregards radical yet plausible changes to the future. This study proposes a new socio-technical methodology to factor in uncertainty over the future within mathematical programming modelling. The methodological approach makes use of foresight and scenario planning concepts to build tailor-made scenarios and scenario fit input parameters, which are then used within mathematical programming models. Health stakeholders and experts are engaged in the scenario building process. Causal map modelling and morphological analysis are adopted to digest stakeholders and experts’ information about the future and give origin to contrasting and meaningful scenarios describing plausible future. These scenarios are then adjusted and validated by stakeholders and experts, who then elicit their best quantitative estimates for coherent combinations of input parameters for the mathematical programming model under each scenario. These sets of parameters for each scenario are then fed to the mathematical programming model to obtain optimal solutions that can be interpreted in light of the meaning of the scenario. The proposed methodology has been applied to a case study involving HHR planning in Portugal, but its scope far extends HHR planning, being especially suited for addressing strategic and policy planning problems that are sensitive to input parameters.info:eu-repo/semantics/acceptedVersio