Reservoir-scale transdimensional fracture network inversion

The Waiwera aquifer hosts a structurally complex geothermal groundwater system, where a localized thermal anomaly feeds the thermal reservoir. The temperature anomaly is formed by the mixing of waters from three different sources: fresh cold groundwater, cold seawater and warm geothermal water. The stratified reservoir rock has been tilted, folded, faulted, and fractured by tectonic movement, providing the pathways for the groundwater. Characterization of such systems is challenging, due to the resulting complex hydraulic and thermal conditions which cannot be represented by a continuous porous matrix. By using discrete fracture network models (DFNs) the discrete aquifer features can be modelled, and the main geological structures can be identified. A major limitation of this modelling approach is that the results are strongly dependent on the parametrization of the chosen initial solution. Classic inversion techniques require to define the number of fractures before any interpretation is done. In this research we apply the transdimensional DFN inversion methodology that overcome this limitation by keeping fracture numbers flexible and gives a good estimation on fracture locations. This stochastic inversion method uses the reversible-jump Markov chain Monte Carlo algorithm and was originally developed for tomographic experiments. In contrast to such applications, this study is limited to the use of steady-state borehole temperature profiles – with significantly less data. This is mitigated by using a strongly simplified DFN model of the reservoir, constructed according to available geological information. We present a synthetic example to prove the viability of the concept, then use the algorithm on field observations for the first time. The fit of the reconstructed temperature fields cannot compete yet with complex three-dimensional continuum models, but indicate areas of the aquifer where fracturing plays a big role. This could not be resolved before with continuum modelling. It is for the first time that the transdimensional DFN inversion was used on field data and on borehole temperature logs as input.DFG, 318763901, SFB 1294, Data Assimilation - The seamless integration of data and models, Assimilating data with different degrees of uncertainty into statistical models for earthquake occurrence (B04)TU Berlin, Open-Access-Mittel - 201

eliberative Democracy in the Writing Classroom and Beyond Author(s): Michael Reich

In this dissertation I explore the consequences of adopting a deliberative pedagogy, based on the study of one or two sample courses taught in 2018 at St. John’s University. The project as a whole argues that the university should be an idea place for students to develop a sense of personal and political agency, and First Year Writing courses organized around deliberation allow students to learn to listen and reason with each other as individuals and as citizens. My first chapter defends the methodology of a humanistic idea of deliberation (a pedagogy not based in classroom drills or Standard English) and where I also worry that the soft and fuzzy notion of deliberation that I practice collides with the measurement of my students’ “progress” on objective rubrics . My second chapter is a case study describing my students’ performance in a deliberative classroom where some of my best students learn to practice deliberation but are unable to define it. My third chapter explains that a deliberative classroom helps overcome student anxiety and what I call “the eyes of deficiency”---rather than thinking of themselves as dull asteriods in a neoliberal universe, deliberation helps them see their power to influence and affect each other. In this chapter I argue that students do not need to go “outside” of class to find their political agency---deliberating and interacting with peers in the classroom itself is a genuine community. Building on my critique of the urge to push our students to find political awareness outside of the classroom, my final chapter is a sustained critique of the “false” face of deliberation found in social media like Facebook. Although many faculty have turned to using social media in class as a means of “making class real” I show the many ways that the Left’s faith in the apparently democratic technologies of social media is well intentioned but terribly misplaced: our students’ writing on social media is being harvested, sensationalized, and exploited against them, and as faculty we need to model practices of genuine listening, empathy, and respect

Do Frictions Matter in the Labor Market? Accessions, Separations and Minimum Wage Effects

We measure labor market frictions using a strategy that bridges design-based and structural approaches: estimating an equilibrium search model using reduced-form minimum wage elasticities identified from border discontinuities and fitted with Bayesian and LIML methods. We begin by providing the first test of U.S. minimum wage effects on labor market flows and find negative effects on employment flows, but not levels. Separations and accessions fall among restaurants and teens, especially those with low tenure. Our estimated parameters of a search model with wage posting and heterogeneous workers and firms imply that frictions help explain minimum wage effects.minimum wage, labor market flows, monopsony, Bayesian estimation