Interaction between staining and degradation of a composite resin in contact with colored foods

Composite resins might be susceptible to degradation and staining when in contact with some foods and drinks. This study evaluated color alteration and changes in microhardness of a microhybrid composite after immersion in different colored foods and determined whether there was a correlation between these two variables. Eighty composite disks were randomly divided into 8 experimental groups (n = 10): kept dry; deionized water; orange juice; passion fruit juice; grape juice; ketchup; mustard and soy sauce. The disks were individually immersed in their respective test substance at 37 ºC, for a period of 28 days. Superficial analysis of the disk specimens was performed by taking microhardness measurements (Vickers, 50 g load for 45 seconds) and color alterations were determined with a spectrophotometer (CINTRA 10- using a CIEL*a*b* system, 400-700 nm wavelength, illuminant d65 and standard observer of 2º) at the following times: baseline (before immersion), 1, 7, 14, 21 and 28 days. Results were analyzed by ANOVA and Tukey's test (p < 0.05). Both variables were also submitted to Pearson's correlation test (p < 0.05). The passion fruit group underwent the greatest microhardness change, while the mustard group suffered the greatest color alteration. Significant positive correlation was found between the two variables for the groups deionized water, grape juice, soy sauce and ketchup. Not all color alteration could be associated with surface degradation.

Estimating thermal performance of cool colored paints

The purpose of this study is to investigate the thermal performance of cool colored acrylic paints containing infrared reflective pigments in comparison to conventional colored acrylic paints of similar colors (white, brown and yellow) applied on sheets of corrugated fiber cement roofing. Evaluated properties are: color according to ASTM D 2244-89, the UV/VIS/NIR reflectance according to ASTM E 90396, and thermal performance by exposure to infrared radiation emitted from a lamp with the measurement of surface temperatures of the specimens with thermocouples connected to a data logging system. Results demonstrated that the cool colored paint formulations produced significantly higher NIR reflectance than conventional paints of similar colors, and that the surface temperatures were more than 10 degrees C lower than those of conventional paints when exposed to infrared radiation. The study shows that cool paints enhance thermal comfort inside buildings, which can reduce air conditioning costs. (C) 2009 Elsevier B.V. All rights reserved.

Modeling of Distributed Control Systems in Intelligent Building based on Colored Petri Nets

Distributed control systems consist of sensors, actuators and controllers, interconnected by communication networks and are characterized by a high number of concurrent process. This work presents a proposal for a procedure to model and analyze communication networks for distributed control systems in intelligent building. The approach considered for this purpose is based on the characterization of the control system as a discrete event system and application of coloured Petri net as a formal method for specification, analysis and verification of control solutions. With this approach, we develop the models that compose the communication networks for the control systems of intelligent building, which are considered the relationships between the various buildings systems. This procedure provides a structured development of models, facilitating the process of specifying the control algorithm. An application example is presented in order to illustrate the main features of this approach.

Solving colored nonograms

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática

Sequencing cutting patterns with colored interval graphs

The problem addressed here originates in the industry of flat glass cutting and wood panel sawing, where smaller items are cut from larger items accordingly to predefined cutting patterns. In this type of industry the smaller pieces that are cut from the patterns are piled around the machine in stacks according to the size of the pieces, which are moved to the warehouse only when all items of the same size have been cut. If the cutting machine can process only one pattern at a time, and the workspace is limited, it is desirable to set the sequence in which the cutting patterns are processed in a way to minimize the maximum number of open stacks around the machine. This problem is known in literature as the minimization of open stacks (MOSP). To find the best sequence of the cutting patterns, we propose an integer programming model, based on interval graphs, that searches for an appropriate edge completion of the given graph of the problem, while defining a suitable coloring of its vertices.

Calliphorid fly (Diptera, Calliphoridae) attraction to different colored traps in the Tingua Biological Reserve, Rio de Janeiro, Brazil

The present study intended to analyze calliphorid attraction to traps painted in a variety of colors and the calliphorid constancy index in the Tingua Biological Reserve, Rio de Janeiro state, Brazil. The Diptera were collected monthly in the Reserve, between 2002 and 2005, totaling 24 samplings. Four traps containing sardines as bait were painted olive green, blood red, black, or white and exposed for 48 h at four equidistant points, 50 m from each other. To determine the calliphorid species constancy, the Bodenheirmer constancy index was used throughout the study. To analyze differences in the total abundance between species and in their color selection, an ANCOVA test with a significance level of 5 % and a Tukey post-test were used, considering the categories species and color as cofactors and climatic variables as co-variables (temperature, relative humidity and precipitation), since the samples were collected over two years. 10,444 insects were captured. Of these, 56 % belonged to the Calliphoridae family, totaling 13 species, with the most frequent species being Laneela nigripes (28.5 %), Hemilucilia semidiaphana (17 %), and Mesembrinella sp. (16.4 %). The other species had frequencies lower than 12 %. Nine species were considered constant, two accessories, and two accidental. The data indicated that the most frequent species presented significant differences between themselves concerning abundance over the captured months, however, the Tukey post-test indicated differences only between a few of them. The black trap presented the higher relative calliphorid frequency (27.34 %), followed by green (25 %), red (24.0 %), and white (23.7 %), although the species abundance in the different colored traps did not differ significantly among themselves. Therefore, there was no Calliphorid flies preference for any of the tested colors.

Jade: a study in Chinese archaeology and religion / by Berthold Laufer. 68 plates, 6 of which are colored and 204 text-figures.

v.10(1912)

On the asymptotic expansion of the colored Jones polynomial for torus knots

In the asymptotic expansion of the hyperbolic specification of the colored Jones polynomial of torus knots, we identify different geometric contributions, in particular Chern-Simons invariant and Reidemeister torsion.