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The research work presented in this thesis comprises an electron microscopy and spectroscopy study of crystal defects that relate to the occurrence of different colours in natural and synthetic diamonds. Two principal lines of investigation have been covered, each with its own objective. The first aims to identify the source of brown colour in natural and synthetic diamond and the second to ascertain the distribution of colour inducing point defects in synthetic diamond. An outline of both areas of research is given below.1) Brown colour in natural and synthetic diamondsColour is a physical property that can be very difficult to characterise in diamond and consequently it receives regular attention from scientists working in the gem industry. In this work, the crystal structures of brown and colourless natural type IIa diamonds are compared along with brown coloured synthetic diamonds manufactured using the chemical vapour deposition (CVD) process. Numerous attempts have been made to trace the origin of brown tints in natural diamond, with the most likely sources, dislocations and nitrogen impurities, ruled out through the application of various analytical techniques. Recently more emphasis has been placed on the study of vacancy related defects in natural diamond and their influence on colour. Differences between the annealing characteristics of brown coloured natural and CVD diamonds suggest that the defect or defects responsible for the brown colour might be different for each type of diamond. The focus of this research work is the analysis of vacancy defects of the order of 1nm in size using aberration corrected scanning transmission electron microscopy (AC-STEM). The sub-nanometre size probe afforded by this technique allows such defect structures to be resolved much more readily than with conventional high resolution transmission electron microscopy (HR-TEM). Small-scale contrast variations are apparent in the lattice images of brown diamonds but not of the colourless variety. These features have been compared to simulated phase contrast images of vacancy clusters in diamond.2) Yellow / Green coloured synthetic diamonds grown using metal solvent catalystSynthetic diamonds for jewellery and industrial applications are routinely manufactured under high pressure-temperature (HPHT) conditions that closely resemble those found during the creation of natural diamonds. Although the manufacturing equipment can vary in design, the HPHT process that occurs inside the reaction vessel remains essentially the same. During processing, the carbon source material is dissolved into a molten metal and then precipitated onto tiny seed diamonds that are added to the reaction chamber. Much time and effort has been expended in refining this process to reduce impurities and defects in the finished diamonds. The presence of remnant transition metal atoms (e.g. nickel) in the crystal structure influences the electronic properties and in particular the colour of the diamonds. The position and configuration of these metallic defects has previously been studied by a variety of analytical techniques, including optical absorption-luminescence spectroscopy and electron paramagnetic resonance spectroscopy (EPR). These studies have proposed a number of optically active nickel centres at both substitutional and interstitial sites. Their association with vacancies and nitrogen atoms has also been highlighted. This work uses electron microscopy and spectroscopy to characterise the nickel defects in synthetic type 1b diamonds.

Online fashion retailers use a wide array of colour names to describe the colours of their products; ranging from simple colour names such as the primary colours to more ambiguous colour names such as cloud and blush. Although many online retailers devote resources to the selection of colour names, no such research exists on the impact this has on online fashion consumers’ behaviours.The impact of colour naming on online fashion consumers is important as fashion and colour have a symbiotic relationship therefore the representation of colour within an online fashion retail setting is crucial. The need for colour naming within online fashion retailing is further intensified by the difficulties of accurately representing colour online and therefore the role of written product information, such as colour naming becomes important. To that end, this research aims to examine the impact of colour naming on online fashion consumers’ behaviours. Cognitive responses are considered to investigate the role of colour naming in providing information. Emotional responses are investigated to determine whether colour naming influences consumers in the same way colours are known to influence consumer behaviour. Finally, cognitive and emotional responses to colour naming are investigated to determine the impact on purchase outcomes within the online fashion retail environment. Qualitative and quantitative research approaches are used to derive empirical data. Through interviews and online questionnaires it establishes evidence to support the importance of colour naming within the online retail environment. Two online questionnaires were administered to determine the impact of colour naming on emotional responses and preferences for the colour naming categories within the online fashion retail environment by using the colour name appeal construct developed for this research. In-depth interviews were carried out to determine the impact of colour naming on cognitive responses and purchase intentions.The findings present a statistical significance for the causal relationship between colour naming and emotional responses. They reveal more complex colour names such as common descriptive, unexpected descriptive and ambiguous colour names are more likely to elicit emotions compared to common colour names. The findings also reveal the same colour naming categories are also more appealing within the context of online fashion retailing.A laddering technique was applied to the interviews. The results reveal that colour naming impacts on purchase intentions via a number of intervening variables; colour information, product information, product perception, information processing technique, aiding the shopping experience, understanding the product, emotional response, personal values, and post-purchase satisfaction. Again the complex colour names are found to have a wider reaching impact. Common and unexpected descriptive colour names did not always provide useful colour information to the consumers.This research presents empirical evidence regarding the impact of colour naming on online fashion consumers, thus shedding light on appropriate colour naming strategies for online fashion retailers.

The altitude at which oxygen supplementation should commence to be administered to aircrew in South Africa, flying in unpressurised aircraft is 12,000 feet. Above that altitude effects of reduced tissue oxygen content (hypoxia) become significant. Vision is particularly sensitive to hypoxia, and it was decided to test visual parameters at 12,000 feet to see if there were any subtle changes which might impair flight safety. It this were so, the level at which oxygen supplementation should commence would have to be lowered. The visual parameters to be assessed, all important in aviation, were colour vision, contrast sensitivity, and the presence of phorias (potential squints). 37 Healthy volunteers had these parameters assessed in an altitude chamber at ground level, 8,000 feet and 12,000 feet. Analysis of the results revealed no clinically significant degradation of vision at 12,000 feet, and it was concluded that the present altitude at which oxygen supplementation should begin (12,000 feet) is appropriate. It was advised that further testing should take place in subjects based at sea level. / Dissertation (MSc)--University of Pretoria, 2006. / School of Health Systems and Public Health (SHSPH) / Unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21611号 / 理博第4518号 / 新制||理||1648(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 正高 信男, 准教授 後藤 幸織, 教授 髙井 正成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Lake browning in the northern hemisphere is endangering crucial ecosystem services. Darker water decreases fish and primary production as well as touristic and recreational values. It furthermore requires intensive treatment to receive safe drinking water. Brownification is connected to iron and coloured dissolved organic carbon (DOC). In Sweden, spruce plantations leak DOC, possibly depending in their DOC rate on tree age. Whereas wetlands are known to purify water and might contribute to the degradation of DOC. This thesis aims to investigate how different land use types and other parameters affect water colour. Ditches flowing through old spruce forests, young spruce forests, and peat wetlands in the Lake Bolmen catchment, southwestern Sweden, were sampled at in- and outlet. Highly significantly positive relationships between DOC, iron and absorbance were found. The relationship was strongest between DOC and absorbance (R² = 0.88; p < 0.001) and weakest between DOC and iron (R² = 0.54; p < 0.001). High variability led to no significant differences in the release of DOC and iron between the three land use types. However, older forests tended to increase DOC and iron loading compared to younger forests. This study suggests that not only spruce forests in general are affecting the brownification, but that several different factors like age and underlying soil type might play a critical role.

El objetivo de esta investigación fue determinar cómo la anomalía perceptiva del color reconfigura la jerarquía visual. Por ello, la hipótesis que se planteó fue que utilizar el contraste en otros elementos gráficos, además del color, permitirá que la gráfica sea mejor percibida por personas con discromatopsia. La metodología utilizada fue, primero el cuestionario para obtener el porcentaje de medios más consumido por la muestra. Segundo, se adaptó el Checklist Sirius según los criterios que cumplían con los fundamentos de diseño de Wong. De esta forma, se recolectaron datos sobre los elementos de diseño que permiten que las personas con discromatopsia perciban con mayor efectividad el producto visual. Los resultados reflejaron que las personas con discromatopsia no presentan diferencias de percepción en cuanto al logotipo de la página web analizada y la compresibilidad de las fotografías. Sin embargo, presentan diferencias entre 16,7% y 33,3% en cuanto a la legibilidad del texto, las zonas en blanco, el uso correcto del espacio visual, los íconos, las secciones de la página, la cantidad de contenido informativo y texturas. En conclusión, se pudo confirmar que existen otros elementos visuales, además del color, que las personas con discromatopsia o tricromatopsia rojo - verde toman en cuenta para interpretar la información de la página web de El Comercio. Tanto la sobrecarga informativa y una interfaz limpia sin ruido visual, son relevantes para que la gráfica sea mejor percibida por personas con discromatopsia en comparación con personas sin anomalías perceptivas del color. / The objective of this investigation was to determine how the perceptual anomaly of color reconfigures the visual hierarchy. Therefore, the hypothesis that was raised was that using contrast in other graphic elements, in addition to color, will allow the graphic to be better perceived by people with dyschromatopsia. The methodology used was, first the questionnaire to obtain the percentage of the media most consumed by the sample. Second, the Sirius Checklist was adapted according to the criteria that met Wong’s design fundamentals. In this way, data was collected on the design elements that allow people with dyschromatopsia to perceive the visual product more effectively. The results showed that people with dyschromatopsia do not present differences in perception regarding the logo of the analysed website and the compressibility of the photographs. However, they show differences between 16,7% and 33,3% in terms of the readability of the text, the blank areas, the correct use of visual space, the icons, the sections of the page, the amount of informative content and textures. In conclusion, it was possible to confirm that there are other visual elements, in addition to color, that people with dyschromatopsia take into account to interpret the information on the website elcomerio.pe. Both, the information overload and a clean interface without visual noise are relevant elements that contribute to make the graphic better perceived by people with dyschromatopsia compared to people without perceptual color abnormalities. / Trabajo de investigación

Ecological indicators are defined as quantifiable metrics that can be used to monitor the state of ecosystems and their response to environmental perturbations. In the global oceans, commonly used indicators are typically based on the presence and distribution of phytoplankton (as indexed by the concentration of chlorophyll-a [Chl-a]), which form the base of oceanic food webs. Phytoplankton phenology (the timing of phytoplankton growth) and phytoplankton size structure are particularly important ecological indicators that can be derived via ocean colour remote sensing. Phytoplankton phenology has a direct control on food availability, which subsequently impacts the survival of higher trophic levels and the structure of marine ecosystems. Meanwhile, phytoplankton size structure can be used to define the major functional groups that ultimately influence marine food web structure, biogeochemical cycling and carbon export. The Red Sea is a relatively unexplored tropical marine ecosystem, particularly in relation to its large-scale biological dynamics. In light of recent evidence of rapid regional warming, the need to monitor the response of the Red Sea to potential future ecosystem modifications is becoming more imminent. Using a combination of contemporary oceanographic tools, with an emphasis on ocean colour remote sensing, this PhD thesis attempts to validate the retrieval of phytoplankton ecological indicators in the Red Sea - specifically phytoplankton abundance, phenology and size structure. The interannual variability of both indicators and their linkages with the regional physical environment are also explored.

This thesis investigates methods for automatic colour transfer when working withgeodata and possible metrics to evaluate the results. Several methods for colourtransfer as well as methods to create an objective measurement were tested. Themethod was evaluated by using a subjective score which was generated by surveyingeight people working with geodata. In the survey the participants were askedto “Rank the images from most similar to least similar, with what you imagine theresult would have been if you would have made the colour transfer manually”.The method with the best overall performance in this study was using colourtransfer in the CIEl   colour space. This method was only matched by a methodsegmenting the image first based on colour information. As the method had thehighest average subjective score but a larger standard deviation than other methods.This was suspected to be largely due to the deviation in quality of the segmentationalgorithm. Using a different method for segmenting the image thismethod might perform even better.The objective measurements proposed in this study were not found to have aconsistent correlation with the subjective measurement, with the exception ofgradient structural similarity. Other methods could have a use in some cases butnot as general colour transfer objective measurement, though a larger study andmore data would be needed to confirm the findings.

Magister Chirurgiae Dentium - MChD / Tooth discoloration has increased the demand by patients to pursue aesthetic treatment options. Bleaching is considered a conservative approach in performing an aesthetic treatment for discolored teeth; however colour rebound and post-operative sensitivity are among the adverse effects associated with vital bleaching. In-office bleaching systems employ the use of high hydrogen peroxide concentrations. The effects of in-office bleaching agents on the degree of colour change and the gender differences in relation to bleaching outcomes are questionable. Post-operative sensitivity can be considered a bleaching side effect and the number of patients that experience it is unknown. Aim: The aim of this study was to assess the outcome of an in-office vital bleaching technique. Objectives: The objectives of this study were to evaluate the degree of colour change after vital tooth bleaching using a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain), using a spectrophotometer (CM-2600d Konica, Minolta) to measure the colour change at each intervention during the bleaching process, to assess the post operative sensitivity during the first week of the intervention, to evaluate the patients' perception of the colour change and to compare it to the colour change (~E) expressed in numeric values and to investigate whether gender differences exist in relation to the outcome of the bleaching procedure. Materials and Methods: The maxillary anterior teeth of 22 patients comprising of 11 males and 11 females were. bleached with a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain). Pre-treatment readings of the two maxillary central incisors using a spectrophotometer (CM-2600d Konica, Minolta) were obtained. Subsequent readings were obtained after scaling and polishing, before bleaching (which was used as a baseline reading), immediately after bleaching, one week and one month postoperatively. Patients were requested to complete a form regarding postoperative tooth sensitivity and their colour perception toward the bleaching treatment. Results: The quantitative effect of the bleaching material on tooth colour showed an increase in L * values and a decrease in a* and b* values, the changes were significant (p values- 0.05) except for the mean value of b* one month after bleaching which was only significant between five and ten percent.