A critical element to the successful operation of activated sludge systems is efficient solid liquid separation achieved by bioflocculation. Bioflocculation refers to the process of microbial aggregation to form activated sludge flocs, dependent on the interaction of exocellular polymeric substances (EPS) to form the matrix that holds microbes, other organics and inorganic particles in a flocculent mass. Numerous factors affect bioflocculation; two key parameters are the Solid Retention Time (SRT) and the substrate loading rate. The latter is related to the two basic designs in activated sludge bioreactor configurations: the Plug Flow Reactor (PFR) and the Completely Stirred Tank Reactor (CSTR). PFR systems have a high substrate loading rate, whereas CSTRs have a low substrate loading rate. Research has shown that the PFR configurations produce better sludge quality, in terms of settleability and dewaterability, and subsequently better effluent quality than CSTR systems. In this experiment, the effect of SRT and substrate loading rate on activated sludge was investigated using bench scale SBRs. PFR and CSTR configurations were simulated by adjusting the fill period to be shorter or longer respectively. A series of SBRs were operated, each with an operating volume of 6L, to obtain data for PFR (fast feed) versus CSTR (slow feed) configurations at 10 Day, 5 Day and 2 Day SRTs. Effluent quality was monitored by measuring effluent TSS, VSS, total and soluble COD and soluble biopolymers. Sludge quality was monitored for the aerobic phase by measuring total and suspended solids, total and suspended volatile solids, Sludge Volume Index (SVI), Capillary Suction Time (CST) and Zeta Potential. Anaerobic digestibility was measured for the sludge produced in these systems by measuring gas production, similar to estimating biogenic methane potential (BMP) and determining short term odor productions, specifically Total Volatile Organic Sulfur Compounds (TVOSCs). As expected the change in feeding pattern and SRTs affected the effluent and sludge quality during the aerobic operation phase. Effluent quality was found to be better for the fast feed system at all SRTs, with all monitored parameters being of similar or significantly lower concentration than for the slow feed system. In terms of sludge quality, the fast feed system was found to retain more of its biomass in solution, indicating better flocculation and settleability in this system. COD was given a lower rank as an effluent quality indicator, since the 5 Day and 2 Day SRT datasets did not correlate well with other datasets, specifically effluent TSS and biopolymers. The data was included because it is believed that the trends were accurate representations of fast versus slow feed system behavior. The trends were comparable to those of effluent TSS and solution biopolymer datasets. In terms of anaerobic digestion potential, the fast feed sludge exhibited greater volumetric gas production per gram of solid at the 5 and 2 Day SRTs. Gas production was similar for both systems at the 10 Day SRT. Total and Volatile Solid reduction were however found to be higher for the slow feed sludge than for the fast feed. This may indicate higher gas and potential odor production per gram of solid degraded for the fast feed sludge. This theory is supported by the odor analyses, which revealed that the fast feed sludge had a higher TVOSC production at each SRT. This was related to the higher protein content of the sludge, indicated by the effluent biopolymers being much higher in protein content than carbohydrates. Shearing, which is part of the solids handling process at most plants, releases these proteins and makes them bioavailable, allowing them to be oxidized to produce TVOSCs and hence higher odors. In conclusion it was found that the fast feed effluent and sludge quality appeared to be overall better at each SRT simulated; the higher TVOSC content may indicate a problem with solids handling, but research has shown that these can be overcome with the addition of iron. Additionally, both systems, the fast and slow feed systems operated better at longer SRTs, with the fast feed system performing better in all cases. The difference was not completely significant in all cases and this is attributed to being a by-product of operating at the optimal M:D salt ratio. This project has strength in terms of its potential for large scale applications. SRT is the considered the most important design parameter and one of the more complicated parameters to manipulate due to its widespread effect on reactor behavior, specifically sludge and effluent quality. Additionally, the fast feed versus slow feed concept is one that has been gaining significant interest, since bioreactor configuration impacts the effluent and sludge quality. Feed configurations have been investigated more frequently within the past decade. The novel approach taken by this project is that it combines these two parameters, both of which are important to large scale plants, both industrial and municipal. / Master of Science

The thesis is focused on slow tourism. The first chapter is dedicated to national and international documents governing sustainable development of tourism, impacts of tourism and approaches to sustainable tourism. It also defines slow tourism, presents the history of its origin, present and future position in the world tourism and the typical participant of slow tourism. Destination of slow tourism and requirements of slow tourists are characterized in this thesis. The next chapter deals with slow tourism potential in the Czech Republic, which is evaluated by statistical analysis.

Repetition is part of our everyday lives: it is all around us, in patterns, art, and habits like having a cup of tea or getting dressed each morning. Repetition, recurrence, and return are also fundamental in nature – there are shifts in the seasons and regular, rhythmic elements, such as the weather, that occur over and over again. In order to repeat you have to remember what you did last time, and memories are intimate and can be associated with personal relationships with objects or clothes; they are not written down but preserved in memories of lived events, which over time become mythologised. In fashion, repetition is linked to imitation: we see how our friends, partners, and people on social media are dressed, and we want to look the same. This has created endless loops of trends, wherein we constantly strive for the new. When we consciously repeat or return there is the possibility to pay attention to our behaviour in relation to consumption and how we spend our time, wear our clothes, and relate to the natural world. This thesis has taken me on a journey which started with the world of repetition, where memories, habits, and nature are visited and revisited. The journey progressed through five destinations/projects at a slow pace: at each, textile art, craft and fashion were explored. Repetition, recurrence, and return were used as methods to explore time and timing in textile making with a focus on the tension and duality between the making and the made.

Slow rate Denial of Service (DoS) attacks have been shown to be a very effective way of attacking vulnerable servers while using few resources. This thesis investigates the effectiveness of mitigation tools used for protection against slow DoS attacks, specifically slowheader and slow body. Finally, we propose a service that cloud providers could implement to ensure better protection against slow rate DoS attacks. The tools studied in this thesis are, a Web Application firewall, a reverse proxy using an event-based architecture and Amazon’s Elastic Load Balancing. To gather data a realistic HTTP load script was built that simulated load on the server while using probe requests to gather response time data from the server. The script recorded the impact the attacks had for each server configuration.The results show that it’s hard to protect against slow rate DoS attacks while only using firewalls or load balancers. We found that using a reverse proxy with an event-based architecture was the best way to protect against slow rate DoS attacks and that such a service would allow the customer to use their server of choice while also being protected.

Background: The slow fashion industry arose as a contraposition to the unsustainable ways of fast fashion, and emphasizes attentive consumption and production. It is characterized by four characteristics - transparency, quality, localism and exclusivity – each described with valuable traits in previous studies. However, current marketing efforts of slow fashion are focused only on two transparency aspects; sustainability and ethics, although previous studies show that these have no influence on consumers consumption choices. Therefore, this study aims to explore which aspects within these four characteristics that are perceived as valuable by consumers, so that a value package model for the consumer perceived valuable aspects of slow fashion can be developed. Purpose: The purpose of this thesis is to develop a new value package model that presents the consumer perceived valuable aspects of slow fashion. Methodology: This exploratory qualitative study was conducted through nine semi-structured interviews with Swedish fashion consumers between the age of 18-26. The participants were selected through convenience sampling, and the interviews resulted in 91 pages of collected data. The data was then analyzed with the help of thematic coding. The findings derived from the study was then used to develop a new value package model; presenting the consumer perceived valuable aspects of slow fashion. Findings: There were six consumer perceived value aspects of slow fashion. These were, in order of highest influence to lowest; classical style, product personality, durability, limited production, security and knowledge. Conclusion: This study contributes with the theoretical implication of a new proposed value package model that displays the customer perceived value aspects of slow fashion. In addition, it provides managerial implications that may help marketers and companies to streamline their marketing efforts of slow fashion.

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

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Slow photon, or light with reduced group velocity, is a unique phenomenon found in photonic crystals that theoreticians have long suggested to be invaluable for increasing the efficiency of light-driven processes. This thesis demonstrates experimentally the feasibility of using slow photons to optically amplify photochemistry of both organic and inorganic systems. The effect of photonic properties on organic photochemistry was investigated by tracing out the wavelength-dependent rate of photoisomerization of azobenzene anchored on silica opals. The application of slow photons to inorganic photochemical processes was realized by molding nanocrystalline titania into an inverse opal structure and investigating its photodegradation efficiency in relation to the photonic properties. Changes in the photodegradation efficiency were directly linked to modifications of the electronic band gap absorption as a result of the photonic properties. The highest enhancement of twofold was achieved when the energy of the slow photons overlaps with the electronic band gap absorption, such that the loss of light due to photonic stop-band reflection was significantly reduced. In addition, the strength of slow-photon amplification with respect to the macroscopic structural order was studied by introducing controlled disorder via the incorporation of guest spheres into the opal templates. For the first time, a correlation between structural order, photonic properties and a photochemical process was established. The ability to combine slow-photon optical amplification with chemical enhancement was further achieved by incorporating platinum nanoparticles in inverse titania opals where the platinum nanoparticles increased the lifetimes of the higher population of electron-hole pairs arising from slow photon. Overall, various important factors governing the slow photon enhancement were investigated in detail, including the energy of the photonic stop band, angle dependence, thickness of the film, degree of structural order, filling fraction of the dielectric material and diffusion of a second medium if present. Theoretical calculations based on scalar-wave approximation in support of the experimental findings were provided wherever possible. The findings provide a blueprint for achieving optical amplification using slow photons in the broad range of photochemical or photophysical processes.

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