Integration of a microbial fuel cell into a green wall for greywater treatment

The aim of this master thesis was to investigate the influence of different reactor media on the electrical and cleaning performance of an electrochemical green wall (EGW). Another aim was to improve electrical power production and the treatment performance of the system investigated in Bezzola (2021). Therefore, the construction, inoculation and operation of the experimental installation based on the findings from Bezzola (2021). The reactor media studied were Vulkaponic (a plant substrate made of pumice and zeolite with a grain size of 3 -7mm), Seramis (a fine-grained expanded clay), and HDPE biocarriers. The electrodes were constructed from biochar and stainless steel mesh. The system was inoculated over a time of 27 days with digested sludge from a wastewater treatment plant. Four measuring campaigns were conducted, at the beginning of which different quantities of greywater were added. The hydraulic retention time for each measuring campaign was 48 hours. The wall with Vulkaponic reactor medium generally resulted in the highest energy production values. This indicates that the substrate choice is a relevant parameter in EGW design. The electrode spacing is another relevant parameter in EGW design. The improved wall design resulted in increased treatment performance compared to the system investigated in Bezzola (2021). By increasing the hydraulic retention time, there is potential for a further improvement in treatment performance. The averaged maximum power per reactor was 5E-05 W/reactor. However, peak power density per reactor varied and could reach as much as 20E-05 W/reactor. Even for a large-scale green wall this power production is way too small to operate an electrical consumer. However, the power measurements could be used as an important indicator to characterize the state of the system in terms of bacterial activity. It could therefore be used in addition to the water quality parameters to optimally monitor, control and feed the system

Negotiating place through food and drink: Experiencing home and away

This study examines how food and drink-related practices mediate tourists’ experiences in destinations. Adopting an interpretivist approach, and drawing on content analysis of travel blogs, the paper contributes to knowledge by demonstrating how the production and consumption of food and drink are used to negotiate feelings, memories and encounters in places. More specifically, we distinguish between three areas of practice: firstly, how situational control is established and articulated through familiarity with foods, but may also be challenged by exposure to disruptive consumption activities. Secondly, how sociability is performed and experienced, including through practices of ‘Othering’ that emerge through food and drink-centred encounters. Finally, how tourists construct new notions of home through eating and drinking routines. We argue that focusing on these areas helps to understand the intersections of food and drink-related practice and tourist experiences in and of place(s)

Rheometry for large-particulated fluids: analysis of the ball measuring system and comparison to debris flow rheometry

For large-particulated fluids encountered in natural debris flow, building materials, and sewage treatment, only a few rheometers exist that allow the determination of yield stress and viscosity. In the present investigation, we focus on the rheometrical analysis of the ball measuring system as a suitable tool to measure the rheology of particulated fluids up to grain sizes of 10mm. The ball measuring system consists of a sphere that is dragged through a sample volume of approximately 0.5l. Implemented in a standard rheometer, torques exerted on the sphere and the corresponding rotational speeds are recorded within a wide measuring range. In the second part of this investigation, six rheometric devices to determine flow curve and yield stress of fluids containing large particles with maximum grain sizes of 1 to 25mm are compared, considering both rheological data and application in practical use. The large-scale rheometer of Coussot and Piau, the building material learning viscometer of Wallevik and Gjorv, and the ball measuring system were used for the flow curve determination and a capillary rheometer, the inclined plane test, and the slump test were used for the yield stress determination. For different coarse and concentrated sediment-water mixtures, the flow curves and the yield stresses agree well, except for the capillary rheometer, which exhibits much larger yield stress values. Differences are also noted in the measuring range of the different devices, as well as for the required sample volume that is crucial for applicatio

Im Dialog mit der Soziokultur: Eine Diskursanalyse der Fachdebatte zur Soziokulturellen Animation

Vielseitig und umtriebig präsentiert sich die Soziokulturelle Animation in ihrer Praxis. Im Rahmen ihrer Projekte und Initiativen werden Partizipationsprozesse moderiert, lokale Akteure und Aktivitäten vernetzt, Jugendtreffpunkte und Kulturhäuser betreut, generationenübergreifende Begegnungen geschaffen, Integrationsprojekte gefördert und Kurs- und Bildungsprogramme organisiert mit dem Ziel das Gemeinwesen weiterzuentwickeln. Bei näherer Betrachtung erweisen sich die Arbeitsfelder und Tätigkeitsbereiche der Soziokulturellen Animation als äusserst vielschichtig und heterogen und lassen sich nur schwer als Einheit fassen. Eine Definition oder zumindest eine einheitliche Beschreibung würde, darüber sind sich viele Involvierte einig, ihre fachliche Weiterentwicklung wesentlich vereinfachen. Zu ihren Eigenschaften gehört es jedoch, dass sie sich nicht nur gegen eine einheitliche Definition sperrt, sondern sich einer solchen geradezu verwehren will. Ein Forschungsprojekt der Hochschule Luzern – Soziale Arbeit hat diese Ausgangslage aufgegriffen mit dem Ziel, einen Beitrag zu leisten für eine wissenschaftsorientierte Weiterentwicklung der Soziokulturellen Animation. Die vorliegende Untersuchung analysiert aus diskursanalytischer Perspektive die Beschreibung und Bestimmung der Soziokulturellen Animation in ihren eigenen fachlichen Grundlagen und deckt damit ihre Konstruktionsbedingungen und -strategien auf. Diese Lesart soll die Soziokulturelle Animation als Gegenstand kritisch analysieren und auszudifferenzieren, um daraus weiterführende Anhaltspunkte und Fragestellungen für den fachlichen Diskurs zu gewinnen

Seeregulierung: von der Hydraulik zum Hochwassermanagement

Aufsatz veröffentlicht in: "Wasserbau-Symposium 2021: Wasserbau in Zeiten von Energiewende, Gewässerschutz und Klimawandel, Zurich, Switzerland, September 15-17, 2021, Band 1" veröffentlicht unter: https://doi.org/10.3929/ethz-b-00049975

Effect of a two-year national quality improvement program on surgical checklist implementation.

Use of the surgical checklist in Switzerland is still incomplete and unsatisfactory. A national improvement program was developed and conducted in Switzerland to implement and improve the use of the surgical safety checklists. The aims of the implementation program were to implement comprehensive and correct checklist use in participating hospitals in every patient and in every surgical procedure; and to improve safety climate and teamwork as important cultural context variables. 10 hospitals were selected for participation in the implementation program. A questionnaire assessing use, knowledge, and attitudes towards the checklist and the Safety Climate Survey were conducted at two measurement occasions each in October/November 2013 and January/February 2015. Significant increases emerged for frequency of checklist use (F(1,1001)=340.9, p<0.001), satisfaction (F(1,1232)=25.6, p<0.001), and knowledge(F(1,1294)=184.5, p<0.001). While significant differences in norms (F(1,1284)=17.9, p<0.001) and intentions (F(1,1284)=7.8, p<0.01) were observed, this was not the case for attitudes (F(1,1283)=.8, n.s.) and acceptance (F(1,1284)=0.1, n.s.). Significant differences for safety climate and teamwork emerged in the present study (F(1,3555)=11.8, p<0.001 and F(1,3554)=24.6, p<0.001, respectively). However, although statistical significance was reached, effects are very small and practical relevance is thus questionable. The results of the present study suggest that the quality improvement program conducted by the Swiss Patient Safety Foundation in 10 hospitals led to successful checklist implementation. The strongest effects were seen in aspects concerning behaviour and knowledge specifically related to checklist use. Less impact was achieved on general cultural variables safety climate and teamwork. However, as a trend was observable, these variables may simply need more time in order to change substantially

Numerical Scaling Studies of Kinetically-Limited Electrochemical Nucleation and Growth with Accelerated Stochastic Simulations

A stochastic atomic-scale lattice-based numerical method based on the Exact Lattice First Passage Time method was developed for the simulation of the early stages of kinetically controlled electrochemical nucleation and growth. Electrochemical reaction and surface diffusion on a hexagonal lattice was accounted for in a pristine physical model system that included edge diffusion along steps, and movement over step edges with Ehrlich-Schwöbel barrier. Five cases were investigated: homoexpitaxy, heteroepitaxy, multi-layer growth, terraces, and confined regions. For each, the influence of the physical parameters, deposition conditions, and system geometry on growth morphology was investigated. Simulation based studies of multilayer surface morphology were able to distinguish between layer-by-layer and island growth modes. On stepped terraces, parameter regions associated with he surface diffusion to deposition flux ratio (D/F) and the Ehrlich-Schwöbel barrier were identified under which deposition occurred either at the step edge or by nucleation and growth of islands on the terraces. The probability of growing single crystals in a small confined region was found to scale with D/F and the radius squared. © 2014 The Electrochemical Society

What contributes to individual differences in brain structure?

Individual differences in adult human brain structure have been found to reveal a great deal of information about variability in behaviors, cognitive abilities and mental and physical health. Driven by such evidence, what contributes to individual variation in brain structure has gained accelerated attention as a research question. Findings thus far appear to support the notion that an individual’s brain architecture is determined largely by genetic and environmental influences. This review aims to evaluate the empirical literature on whether and how genes and the environment contribute to individual differences in brain structure. It first considers how genetic and environmental effects may separately contribute to brain morphology, by examining evidence from twin, genome-wide association, cross-sectional and longitudinal studies. Next, evidence for the influence of the complex interplay between genetic and environmental factors, characterized as gene-environment interactions and correlations, is reviewed. In evaluating the extant literature, this review will conclude that both genetic and environmental factors play critical roles in contributing to individual variability in brain structure