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Människor påverkas av ljus både fysiskt och psykiskt. Eftersom en stor del av vårt liv tillbringas inomhus, är ljussättningen i innemiljöer en viktig faktor som bidrar till vårt välmående. Barn är särskilt känsliga för ljus och dess effekter, därför är ljussättningen i en skolmiljö speciellt viktigt. Ljussättningen i skolan påverkar eleverna dagligen, och spelar en betydande roll i elevernas välmående och prestation. I dagsläget är inte ljussättning något som prioriteras i kommunala grundskolor i Stockholm - det innebär att ljusplaneringenen inte är optimalt utformad utifrån elevernas behov och lokalens form, funktion och förutsättningar. Riktlinjer för ljussättning och belysningskrav som ställs av BBR och SIS är endast på allmän och grundläggande nivå. Examensarbetet är en fördjupning i ljus och dess planering och gestaltning i skolmiljö. Syftet med arbetet är att omvandla en skolmiljö genom att förändra ljussättningen, med hänsyn till både dagsljusinsläpp och artificiell ljus. Arbetet handlar om att anpassa ljussättningen i ett rum utifrån rummets funktion, egenskaper och behov för att skapa de bästa möjliga förutsättningar för elevernas välmående och fokus. Arbetet innefattar en fördjupning inom ljussättning i skolmiljö, en analys av olika rumstyper, en beskrivning av ljusbehov i de olika rumstyperna, analys av fysiska 3D modeller, illustrationer, ljussektioner, rumsplan samt studier och beräkningar från programmet Relux (datorprogram för ljussimulering). Med den teoretiska fördjupningen inom ljussättning i skolmiljö som grund, skapades fyra koncept för fyra olika rumstyper: matsal, klassrum, korridor och bibliotek. Dessa koncept skapades för att kunna användas som underlag för planering av liknande lokaler i skolmiljö. Arbetet innefattar även en tillämpning av de skapade ljuskoncepten. Koncepten tillämpades i Vällingbyskolan. Resultatet blev då ett förslag på omplanering av ljuset i Vällingbyskolans bibliotek, korridor, matsal och i ett av klassrummen. Detta grundades på en platsanalys (nulägesbeskrivning) och på anpassningen av ljuskoncepten till dessa specifika lokaler. Alla planerade lokaler uppfyller BBR och SIS standard för belysning, samt följer riktlinjerna som anges i planeringsguiden “Ljus och Rum, planeringsguide för belysning inomhus”, utgiven av Ljuskultur. Rummens ljussättning planerades utifrån rummens funktion, egenskaper och förutsättningar. Belysningsstyrka och färgtemperatur anpassades i varje rum beroende på synuppgifterna som tillkommer där. Självstyrd belysning och motoriserade gardiner implementerades i några av rummen. Gestaltning av dagsljus och jämn belysning prioriterades i alla rum. Resultatet presenteras med Illustrationer, ljusplan, ljussektioner, solstudier, beräkningar från programmet Relux och beskrivande text. / Light affects people both physically and psychologically. Since a big portion of our lives is spent indoors, the lighting design of indoor spaces has become an important factor contributing to our well-being. Lighting design in school environments is particularly important, since children are very sensitive to light and susceptible to its effects. The lighting design in schools affects students on a daily basis, and plays an important role in the students’ well-being and performance. Currently, lighting design isn’t something that’s prioritized in public middle schools in Stockholm - the light planning isn’t usually optimally designed to fit the needs of the students nor to fit the function and characteristics of the building. Guidelines and rules for light planning indoors that are set by BBR and SIS are quite general and on a very basic level. Further research is required in order to properly plan indoor lighting for a school environment. This Thesis includes further research in lighting design, with a focus on lighting design for schools. The aim of the project is to transform a school environment through lighting design, considering both natural and artificial light. The project’s goal is to adapt the lighting of a room to fit its function and its characteristics, in order to create the best conditions for students’ well-being and their ability to focus. This project includes an elaboration on lighting design in schools, an analysis of different room types in a school setting, a description of the different requirements the different rooms have, an analysis of the 3D light models, illustrations, light sections, floor plans, and studies and calculations made in Relux (an application for light simulation). Four lighting- concepts for four different types of rooms in school settings were developed. The rooms used for the lighting concepts are a dining hall, a library, a classroom and a corridor. These concepts were created to be used as prototypes in the planning of similar rooms in different schools. The project also includes an application of the concepts/prototype rooms. The concepts were applied to Vällingbyskolan. The result was a proposal of an improved light design plan in the dining hall, library, corridor and in one of the school’s classroom. The proposal was based on a place analysis of the school and on an adaptation of the developed concepts.All the planned rooms meet the standards set by BBR and SIS, while also following the recommendations and of ““Ljus och Rum, planeringsguide för belysning inomhus”, a guideline for the planning of lighting system indoors developed by the light design magazine “Ljuskultur”. The lighting system is planned to fit the room’s function and characteristics. The implementation of natural daylight and evenly distributed lighting are prioritized in all rooms. The intensity of illumination and the color temperature of the lighting system are considered and made to fit the room and its specific function. The result is presented as illustrations, light plans, light sections, sun studies and RELUX calculations and analysis, as well as a descriptive text.

Eyes allow us to see and gather information about the environment. Eyes mainly act as an input organ as they collect light, but they also can be considered an output organ as they indicate the subject's gaze direction. Using the orientation of the head and the position of the eyes, it is possible to estimate the gaze path of an individual. Gaze estimation is a fast growing technology that track a person's eyes and head movements to "pin point" where the subject is looking at on a computer screen. The gaze direction is described as a person's line of sight. The gaze point, also known as the focus point, is defined as the intersection of the line of sight with the screen. Gaze tracking has an infinite number of applications such as monitoring driver alertness or helping track a person's eyes with a psychological disorder that cannot communicate his/her issues. Gaze tracking is also used as a human-machine interface for disabled people that have lost total control of their limbs. Another application of gaze estimation is marketing. Companies use the information given by the gaze estimation system from their customers to design their advertisements and products. / Electrical and Computer Engineering

<p> Photocatalytic TiO2 coated paper was prepared as antibacterial paper to investigate bactericidal activity of TiO2 in the presence of UV light. When TiO2 exposed to UV light, it produced hydroxyl radicals which were strong oxidative groups and could damage the cell wall causing death of bacteria. The goal of this work was to develop a promising method for microbiological examination of antibacterial paper and to test the disinfection properties of photocatalytic TiO2 coated paper after UV illumination.</p> <p> Three different methods were modified to test antibacterial effect of TiO2 coated paper. The disk diffusion method, the washing method, and the membrane filter method. It was found that disk diffusion technique would not work because of insolubility of TiO2 in water but it could be used for any other antibacterial paper that consisted water soluble agent. The results from membrane filter method agreed with those of washing method showing the reduction of E.coli colonies for TiO2 coated paper after exposure to UV, comparing to blank paper.</p> <p> With use of washing method, it was shown that by changing some functions such as: increasing TiO2 content on the paper, increasing UV irradiation time or UV intensity, survival ratio of the bacteria decreased.</p> / Thesis / Master of Applied Science (MASc)

The concept of "visual fatigue" has been studied for 70 years or more. In that time, no single metric of measuring visual fatigue nor one agreed-upon set of tasks to induce visual fatigue has been settled upon. Not even a robust definition of visual fatigue has been established. This research worked to solve some of those problems. This research first set out to develop an index of visual fatigue that could be used effectively in quantifying the subjective experience of visual fatigue. Then it sought to create a set of measurable tasks, representative of office work, that would induce visual fatigue. Taking these two developments, an experiment using human participants was conducted to validate these developments and work toward solving two issues in the visual fatigue field: how visual display technology and ambient illumination affect the onset of visual fatigue. A 4x4 within-subjects design was developed and executed to study how these two independent variables affected ratings of visual fatigue, performance on the task battery, subjective image quality judgments, and contrast sensitivity shifts. Two cathode ray tube (CRT) and two active-matrix LCD (AMLCD) monitors were used in this study. While many instances of the monitors as a whole caused significant differences in reports of visual fatigue, performance, subjective image quality, and contrast sensitivity loss, only a slight effect of display technology was found. Four of eleven visual fatigue and two of eight subjective image quality dimensions showed that the LCD monitors induced more visual fatigue and were rated poorer than the CRT monitors. Ambient illumination levels of 0, 300, 600, and 1200 lux affected all four groups of dependent variables. On the whole, lighting caused visual fatigue, with "watery eyes" and "glare from lights" being adversely affected by brighter lighting. The 0 and 1200 lux were associated with the worst performance, while 300 lux was associated with the best performance. Subjective image quality was affected by lighting, with increasing lighting causing bothersome screen reflections and more temporal (e.g., flicker and jitter) distortions; 600 lux induced more reports of image sizing anomalies. Finally, it caused significantly worse shifts at the 6.0 c/deg spatial frequency on the contrast sensitivity test. The data show that lighting of 300 lux is the best of these four illumination levels. The results of this study not only contribute to the body of research in the areas of display technology and ambient illumination, but several developments of this research are offered to the research community: a complete survey metric of visual fatigue, a standardized battery of tasks for studying visual fatigue and image quality, and a comprehensive subjective image quality survey. / Ph. D.

<p dir="ltr">Spatial heterogeneity is ubiquitous across life and the universe; the same is true for phase-separating pharmaceutical formulations, cells, and tissues. To interrogate these spatially-varying complicated samples, simple analysis techniques such as fluorescence recovery after photobleaching (FRAP) can provide information on molecular transport. Conventional FRAP approaches localize analysis to small spots, which may not be representative of trends across the full field of view.</p><p dir="ltr">Taking advantage of strategies used for structures illumination, an approach has been developed to use patterned illumination in combination with FRAP for probing large fields of view while representatively sampling. Patterned illumination is used to establish a concentration gradient across a sample by irreversibly photobleaching fluorophores, such as with the simple comb pattern photobleach presented in Chapters 1 and 4. Patterned photobleaching allows spatial Fourier-domain analysis of multiple spatial harmonics simultaneously. In the spatial FT-domain the real-space photobleach signal is integrated into puncta, greatly increasing the signal to noise ratio compared to conventional point-bleach FRAP. The order of the spatial harmonic is directly related to the length-scale of translational diffusion measured, with a series of harmonics accessing diffusion over many length scales in a single experiment. Measurements of diffusion at multiple length scales informs on the diffusion mechanism by sensitively reporting on deviations away from normal diffusion.</p><p dir="ltr">Complementing the physical hardware for inducing patterned illumination, this dissertation introduces novel algorithms for reconstructing spatially-resolved diffusion maps in heterogeneous materials by combining Fourier domain analysis with patterned photobleaching. FT-FRAP is introduced in Chapter 1 for interrogating phase-separating samples using beam-scanning instrumentation for comb-bleach illumination. This analysis allowed disentangling separate contributions to diffusion from normal bulk diffusion and an interfacial exchange mechanism only available due to multi-harmonic analysis. The introduction of a dot-array bleach pattern using widefield microscopy is presented in Chapter 2 for high-throughput detection of mobility in simple binary systems as well as for segmentation in phase-separating pharmaceutical formulations. The analysis becomes more complicated as more components are added to the system such as a surfactant. Introduced in chapter 3, FT-FRAP with dot-array photobleaching was shown to be useful for characterizing diffusion of phase-separating micro-domain smaller than a single pixel of the camera. Supported by simulations, a biexponential fitting model was developed for quantification of diffusion by multiple species simultaneously. Chapter 4 introduces imaging inside of 3D particles comprised of an active pharmaceutical ingredient (API) in microencapsulated agglomerates which exhibited strong interfacial exchange. Multi-photon excited fluorescence enabled imaging a small focal volume within the particles.</p>