JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2008 | Volume:2 | Issue:1|Papers Count:7

In this paper, the linear interpolation technique is applied to reconstruct the reflectance curves of the Munsell color chips from their tristimulus color coordinates. Interpolation method has been applied by using a look-up table (LUT) for transforming color values from the color space to the second multi-dimensional spectrophotometric domain. Tristimulus values of Munsell color chips have been used for creating the look-up table. Results of recovery are evaluated by the metamerism index under two different standard light sources and the root mean square (RMS) error. The results showed that the metamerism indices between the actual and the reconstructed curves were totally small. The negligible values of the RMS error also indicate the suitability of the proposed method.

In this work, the RTV coatings with different levels of ATH and silica fillers were applied to porcelain suspension insulators for a comparative study of the performance of coated and uncoated porcelain insulators. These coated insulators were exposed to different electrical tests. The test results have been reported based on the role of ATH and silica fillers. The measurement of contact angle is also used to investigate the hydrophobicity properties of coatings. TGA is used to investigate the effect of ATH addition to the samples. It has been found that if only ATH is used as filler, the best performance belongs to the sample with 70pph ATH. Addition of 10pph silica also improves the performance of coatings with ATH level between 35 to 70 pph. But it should be mentioned that addition of 10pph silica to samples with higher ATH level (more than 70pph ATH) wasn’t beneficial.

In this paper, nanocristobalite was prepared by simple heat treatment of amorphous silica at 1470oC for 2 hours. The XRD results confirmed that amorphous silica changed to cristobalite completely. The prepared cristobalite and crystaline microsilica (quartz) and two types amorphous of nanosilica (untreated and surface treated) were used to improve the mechanical properties of a two component polyurethane automotive clear coat. The effect of the nanosilicas and microsilica on the optical and mechanical properties of the clear coat was studied. It was revealed that all of the silicas added improved the hardness properties of the coatings, but some of them had a negative effect on the optical properties. Nanosilica (surface treated) improved optical propertiy and wear resistant.

In this paper, the decolorization of colored textile wastewater was investigated using Photo-Fenton process. Acid Blue 92 (AB92) was used as an azo acid dye model. The effect of decolorization parameters such as ferrous ion concentration, dye concentration and sodium salts (acetate, nitrate, carbonate and bicarbonate) were investigated. The maximum iron (II) concentration was set to maximum allowable discharge level to environment. The rate of decolorization reaction decreased by increasing dye concentration and in the presence of sodium salts. For a comparative study, decolorization of AB92 was also performed by photocatalysis using immobilized titania and combined Photo-Fenton - photocatalysis processes. The Photo-Fenton process had the greatest decolorization rate in comparison to photocatalysis and combined Photo-Fenton - photocatalysis processes.  The results showed that the Photo-Fenton process had the decolorization capability of colored wastewater at different dye concentrations and in the presence of sodium salts.

In this paper, nanosilver layers for solar mirrors were deposited on white glass substrates (~4 mm thick) by DC magnetron sputtering method. The effect of the substrate temperature about (300-500 K) on the nano Ag film growth was studied. Their properties were characterized by XRD and SEM. The Ag layer followed the Torenton structural zone model at different substrate temperatures. The results showed the silver sputterd particle grow with increased the temperature but dislocation density decreased with it.

In this research, a brown spinel based pigment has been synthesized. At first a reference brown pigment has been analysed by XRF, XRD and SEM. Then according to these results, various formulations have been prepared and calcined at deferent conditions. The obtained pigments have been analysed by CIE-Lab, XRF, XRD, SEM and LPSA. The prepared pigments as well as the reference pigment have been added to the glaze. Then, after glost firring, their colors have been measured in CIE-Lab system. The results showed that color quality of the optimized pigment (i.e. ZnO/Cr2O3=1.6, Fe2O3/ Cr2O3=0.87 and Cal at 1250oC) prepared it in this work was comparable with the reference one. The prepared pigment showed good thermal and chemical stability.

In this work silica nanoparticles were synthesized in a semi-continuous precipitation method. The effects of reaction time, concentration of reactants and pH were investigated on oil absorption and specific surface area (SSA) of synthesized nanoparticles in a full factorial design of experiment (DOE) with three parameters. In this design, each parameter was investigated in two levels. The reaction time and pH were main parameters that affecting on particles oil absorption. BET results showed that all of the three parameters could significantly affect the specific surface area of the product. Morphology and particle size distribution of precipitated nanosilica were investigated using transmission electron microscopy. The particle size of the synthesized silica nanoparticles was observed to be smaller than 20nm. The average specific surface was found to be of 230m2/g and average oil absorption 235g/100g. The thermo gravimetric analysis result showed that the total silanol density in the nanosilica was 15nm-2.