Este estudo avaliou a influência de três iluminantes e da diferença na rugosidade superficial de réplicas de dentes artificias na percepção da diferença de cor entre profissionais da Odontologia e verificou se houve variação na opinião de 20 profissionais uma semana após a primeira avaliação. O único critério de exclusão dos participantes foi a deficiência na visão cromática, avaliada através da versão simplificada do teste de Ishihara. Dos 117 profissionais entrevistados, 6 (5,1%) homens e 11 (9,4%) mulheres foram excluídos do estudo, pois identificaram incorretamente 1 ou mais pranchas da versão simplificada do teste de Ishihara. Neste estudo foram utilizados 4 pares de réplicas de dentes artificiais, sendo que cada par foi confeccionado em resina composta nas cores A1, A3, B1 ou B2, porém uma réplica apresentava superfície lisa e a outra, superfície rugosa. Todas as avaliações foram realizadas em cabine de luz sob os iluminantes D65, A e F2. Para cada iluminante, os participantes foram questionados se havia diferença de cor entre as réplicas. Após uma semana, todo o experimento foi repetido por 20 profissionais selecionados aleatoriamente. A análise dos resultados sugeriu que os iluminantes e a diferença na textura superficial influenciaram a percepção da diferença cor entre as réplicas e que após uma semana houve variação na opinião dos observadores. / This study evaluated the influence of three different illuminants and the difference on surface roughness of artificial teeth replica on the color difference perception among dental professionals and if there were variations on 20 professionals opinion 1 week after the first evaluation. The color vision deficiency was the only exclusion criteria used and a screening for color defective vision was conducted by using the simplified version of Ishihara test. Among the 117 professionals interviewed, 6 (5.1%) men and 11 (9.4%) women who missed 1 or more plates did not take part in this study. The test was composed by 4 pairs of artificial composite resin teeth replicas was confectioned with the same color A1, A3, B1 or B2, but the surface of one replica was smooth and the surface of the other one was rough. All the evaluations were conducted in light booth with D65, A and F2 illuminants. In each illuminant the participants were asked if there were color difference between the replicas. After one week, all the experiment was repeated by 20 participants randomly selected. The analysis of the results suggested that the illuminant and the difference on surface texture influenced the difference color perception between the replicas and reaffirm that the professionals opinion varied after one week of the first evaluation.

Context Colors are an important aspect of video games, they have a key roll when designing everything from characters to world objects. Therefore designers and developers need to know what colors that are preferred over others. Objectives This paper tries to determine which color setting that is the most preferred on a game avatar. Methods To do this an experiment conducted with 15 participants. They conducted a two alternative forced choice test (2AFC) with 236 pairs of pictures. All of the 236 pairs were based on color harmonies and displayed on an avatar and a cube. The different color harmonies that were used sprung from the three primary colors of the RGB-color wheel that worked as a base in this experiment. The results that were collected went through a Chi-square test. Result Some interesting results were generated from the experiment. For instance, the most preferred color harmony for the avatar was the split complementary with the base in the primary color red. Second to that was the color harmony triad, built on the three primary colors red, green and blue. The color harmonies that had their base in the color green were with zero percent the least preferred of all harmonies. On the other hand the color harmonies that had their base in the color blue were generally the most preferred among all of the harmonies. Conclusion The main conclusion that was made and that could answer the research question was that the most preferred color harmony for the avatar was split complementary red. There were also some conclusions made that could help to create a more general preference for all kind of avatars, if this experiment would be remade on a larger scale.

Ph.D. / Please refer to full text to view abstract

Two experiments investigated the effects of pre-receptoral absorption and levels of illumination on colour vision. Simulation filters approximating lens and macular pigment changes were constructed on the basis of previous investigations. Experiment I investigated the effects of these filters on young, normal subject performance. Shifts were found in the direction of ageing populations but not as great as is required. Experiment II investigated the additional effect of reductions in illumination. The two experimental manipulations together account for senile decreases in discrimination at slightly higher levels than previously reported / Arts, Faculty of / Psychology, Department of / Graduate

This study investigated color discrimination as a possible localized function of right or left cerebral hemispheres in humans. Previous studies have shown conflicting results. Studies implicating the left hemisphere have contaminated color discrimination with verbal-symbolic ability. Other studies implicating the right hemisphere emphasized color-matching ability. This study pointed out the importance of response latency as well as accuracy and also the importance of testing the data for meeting the assumptions of the statistical technique utilized. It was concluded that color discrimination is normally a right-hemisphere function in right-handed individuals. Differences in individual ability, although large, were not found to be systematically related to sex or eye dominance, but may be learned individual differences. The study further pointed out the inappropriateness of referring to a major or dominant cerebral hemisphere without stipulating which function is being considered.

Atriplex hortensis L., also known as orach, is a leafy vegetable from the Amaranthaceae family, which has historically been consumed as a potherb, like spinach. The brightly colored leaves are a source of high quality protein, but may also be of interest as a potential source of natural food pigments. An aqueous extraction was obtained from the freshly harvested leaves of the'Triple Purple' variety of A. hortensis. The extract was spray-dried into a powder, and individual pigments were analyzed using HPLC and LC-MS. The powder was also included as a color additive in a typical stabilizer/sweetener preparation and mixed into plain yogurt. Two batches of colored yogurt were held under light and dark conditions and tested for pH and color (L*a*b*) every 15 days. A visual sensory panel was performed on days 0, 45, and 90 to evaluate the color acceptance.A total of three types of betacyanins and six types of anthocyanins were tentatively identified by HPLC and/or LC-MS. Orach pigments in yogurt were not stable under full light exposure. The color of samples exposed to light degraded within days. There were statistically significant differences found in L*a*b* scores in the dark treatment, beyond 30 days; but these modest changes in dark-stored samples were not found to be statistically significant in the consumer sensory panel. The tentative identification of both anthocyanins and betacyanins in orach is a novel finding in botanical research, as the literature indicates that these two pigment classes are mutually exclusive. The application of heat during pigment extraction, spray drying, and yogurt color additive preparation, did not appear to appreciably affect stability of orach pigments, indicating that orach extract could be used as a color in different process applications, if protected from light.

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The goal of this research was to design and test an experimental setup capable of performing a TIG welding process and acquiring temperature measurements near the weld with the use of an infrared spot sensor. The data collected can then be used to validate a computer simulation that models the exact same process. An experimental setup was built, and preliminary temperature data were collected. It was determined that infrared measurements taken at the arc contain excessive amounts of interfering radiation emanating from the welding zone. The optimal angle of orientation is normal to the weld line. In this way an infrared spot sensor can be focused on an area just down weld of the arc where the temperatures remain relatively high and thermal gradients, although still large, are at a minimum. Additional data were collected from thermocouples to validate the infrared sensor results and also to provide additional data that can be compared to a computer model. Sources of error were identified and recommendations were made as to how they can be avoided or minimized. / Master of Science