JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2018 | Volume:12 | Issue:4 |Papers Count:10

Performance, level of consciousness and concentration of staffs at work could be affected by a series of color physics parameters among which parameters related to lighting of work environment could be noticed. Physical factors in working environment has direct effect on the visual, psychological and health needs of individuals to improve the quality of all the places, especially indoor spaces, lighting as a physical factor in working environments should be considered. If the quality and quantity of lighting of working room cannot be provided properly, it can be a risk factor for the emergence of some complications such as visual, physical and mental disorders. In this study, the relationship between the psychological characteristics of the staff in their working room and the physical parameters associated with the used light sources, i. e. illuminance and correlated color temperature (CCT) were considered. The questionnaire of the Pittsburgh sleep quality and the Karolinska sleepiness scale as well as the selective & divided attention test were used for the psychological analysis. The parameters of illumination were measured in time intervals as at the first, mid, and end of the work shift for 21 rooms with the artificial light sources. The results showed that the low consciousness level can be improved to some extent by the factors such as correcting lighting conditions and light sources in terms of intensity of lighting and correlated color temperature. J. Color Sci. Tech. 12(2019), 241-250© . Institute for Color Science and Technology.

In this article, role of temperature in rutile TiO2 nanorod synthesis by hydrothermal method was investigated due to one-dimensional oriented nanostructures application importance. Synthesis was studied at three level of temperatures such as 125, 150 and 175 º C. The result of XRD, SEM and UV-Visible tests showed that crystallinity and crystallite size would increase in order to increment temperature, furthermore, the length and partly diameter of nanorods would enhance when temperature increased. Indeed, the length of nanorod at 125 º C was about 0. 5 microns, however, at 175 º C was 1. 7 microns. Moreover, photocatalytic activity of nanorods by measurement the degradation of methylene blue would increase but the efficiency would decrease when the temperature enhanced. Absorption diagram at different wavelengths demonstrated that the synthesized TiO2 nonarods had no absorption in UV region and also absorption decreased at higher wavelengths. The band gap for all samples were near 3 ev. The optimum temperature for reaching to best efficiency was 150 º C. J. Color Sci. Tech. 12(2019), 251-259© . Institute for Color Science and Technology.

Nano-sized Zn-Al Layered Double Hydroxide crystals were synthesized using a modified two step process of "fast coprecipitation and subsequent controlled hydrothermal method". Dynamic light scattering result showed a particle size of 71. 68 nm to the obtained stable and translucent suspension. The structural morphology of the deposited nano-crystallites was studied using field-emission-SEM images. The phase purity of the as-synthesized LDH material and its calcined product was determined by using XRD, FT-IR and TG-DTG analyses. A perovskite solar cell was fabricated using the LDH paste as mesoscopic layer for the first time. To have a vast observation on the solar cell efficiency, a series of LDH-based perovskite solar cells were fabricated using the admixture of LDH and TiO2 with (100-x)LDH + xTiO2 (x = 0, 25, 50, 75) admixture recipe. The solar cell parameters showed an increase in the efficiency of the cell as the LDH content decreased in the admixture composition. J. Color Sci. Tech. 12(2019), 261-269© . Institute for Color Science and Technology.

Chromium oxide based nanopigments are widely used in many fields such as coating, wear and wear resistance materials, H2 absorbent material and advanced colorants. In this paper, chromium oxide-based nano pigments of Cr2O3, CoCr2O4 and Al2O3-2Cr2O3 were synthesized via hydrothermal method and then calcinated at 770 ° C for 4 h. The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results of XRD analysis show that Cr2O3 and CoCr2O4 were crystallized in a single-phase structure while Al2O3-2Cr2O3 was crystallized in multi-phase structure. SEM images show that the pigments are nanostructures and the average particle size of Cr2O3, CoCr2O4 and Al2O3-2Cr2O3 nanopigments were about 57, 33 and 83 nm, respectively. The samples were also characterized by diffuse reflectance spectroscopy (DRS) and CIE-L*a*b* colorimetric measurement. The nanopigments obtained in this work presented different colors such as green and greenish yellow colors. J. Color Sci. Tech. 12(2019), 271-280© . Institute for Color Science and Technology.

Photocatalytic process is one of the best methods for degradation of organic pollutants from wastewater. The separation of photocatalyst from the treated wastewater is of great importance from engineering point of view. In this article, the anatase synthesized by sol-gel method was coated on meta-kaolin support through the polymeric binders. The photocatalytic activity of fabricated packed beds was evaluated by degradation of wastewater contaminated by methylene blue under solar irradiation using UV-Vis spectroscopy. Two polymeric binders employed to coat titanium dioxide on extruded ceramic supports. Moreover, the dye degradation kinetics in the presence of packed beds and anatase powder were studied to understand the role of support on wastewater treatment. The structure of support was identified by XRD and FESEM before and after photocatalyst coating. The obtained results showed that the 3-(Aminopropyl) triethoxysilane is favorable to be applied as a binder in comparison to methacrylic acid. Approximately, 65% of methylene blue is degraded during 60 minutes. J. Color Sci. Tech. 12(2019), 281-292© . Institute for Color Science and Technology.

In this research, blue pigments are evaluated in terms of their chemical composition and morphology in two manuscripts of the Safavid era. For this purpose, microscopic approach with Dino Light and SEM and EDX are used. The results of the element analysis showed three types of blue pigments. In natural lazurite, there is calcium. However, the element does not exist in artificial lazurite. In the chemical composition of western lazurite, there was cobalt that makes it distinct from other lazurite. SEM images also showed morphological components for their structure, so that there were crystal disparate particles for natural and western lazuli, and round shapeless particles were identified in artificial lazurite. J. Color Sci. Tech. 12(2019), 293-304© . Institute for Color Science and Technology.

Recently, the use of high reflective pigments as cool pigments is taken into consideration to reduce energy consumption in buildings, especially in tropical regions. The aim of this study is to synthesize the iron oxide (hematite)-titanium dioxide pigment and investigate the infrared reflection properties in different synthesis conditions. For synthesis, combination of sol-gel and co-precipitation method was used. The effect of synthesis method and calcination on IR reflection was investigated. Compositions of products and powder morphology were analyzed using X-ray powder diffraction (XRD), Field emission scanning microscopy (FESEM) and Transmission electron microscopy (TEM) methods. The results of XRD showed that titanium oxide delayed the crystallization of iron oxide. By examining the reflection spectra of the powders, it was observed that the infrared reflection increases significantly by crystallization. Overall it was seen that the Fe2O3@TiO2 core shell structure can be considered as a suitable cool pigment with good NIR reflection for energy saving applications. J. Color Sci. Tech. 12(2019), 305-313© . Institute for Color Science and Technology.