• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.343-357
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• 1999

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600 hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smalt or color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order of non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light absorber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.3
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• pp.105-110
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• 2009

Yellow sand (or Asian dust) occurs mainly in spring in East Asia. Yellow sand from China and its surrounding regions transports air pollutants, such as aerosols, ozone, and heavy metals. The outdoor workers are frequently exposed to heavy metals during yellow sand phenomenon. This study was carried out to investigate the heavy metal levels in blood among 75 outdoor workers (exposed group) and 86 indoor workers (controled group) in Gyeonggi province from March 2008 to May 2009. Heavy metal levels in blood were analyzed by atomic absorption spectrophotometer. Mean blood lead levels in exposed group and controled group were $5.19{\pm}1.64{\mu}g/dL$, $4.24{\pm}1.34{\mu}g/dL$, respectively. Mean blood cadmium levels in exposed group and controled group were $1.28{\pm}0.89{\mu}g/dL$, $0.90{\pm}0.59{\mu}g/dL$, respectively. Lead and Cadmium levels in blood of exposed group were significantly higher than those of controled group. In the comparison of smoking status, lead and cadmium levels of smokers were significantly higher than those of non-smokers. In conclusion, the heavy metal levels of outdoor workers were significantly higher than those of indoor workers. And smoking was hazardous factor to elevate heavy metal levels in blood.

• YAKHAK HOEJI
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• v.13 no.1
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• pp.33-37
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• 1969

A new organic reagent, 1-isonicotynyl-2-furfurylidene hydrazine synthesized from isonicotinic acid hydrazid and furfural, gives yellow liquid with cadmium (II). Cadmium complex of the reagent is soluble in water with yellow coloration. The complex has a maximum absorption at 363 m${\mu}$ and molar ratio of cadmium to reagent was estimated as 1:1 by continuous variation method and slope method. Molecular extinction coefficient and apparent formation constant of this complex was spectrophotometrically determined. K=4.48 $\times$ 10$^{3}$ (Babko's method) K=1.33 $\times$ 10$^{3}$ (Anderson's method)

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.504-506
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• 2005

• Journal of Nutrition and Health
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• v.12 no.3
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• pp.25-32
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• 1979

In order to investigate harmful trace elements in ford additives used in food processing the contents of Copper, Lead, Cadmium, Chromium, Manganese, Nickel and Iron are determined by Atomic Absorption Spectrophotometer. These Elements are Extracted with APDC-MIBK extract method. Samples are collected from the food Industrial companies in Korea. Samples studied as shown in Table 1 are food colors(3-samples, Flavoring Agents(7-samples), Acidifiers(4-samples) Baking Powders(4-samples), Emulsifiers(2-samples), Thickeners(2-samples), Antioxidants(2-samples), Intensifiers(2-samples), Seasonings(3-samples), modifiers (10-samples) Most of the food additives contained comparatively a little small amount of harmful trace elements. However, the contents of harmful trace elements of Sodium Carbonate, Food Yellow No.5, Food Blue No.1, Food Red No.2 and Alkalies added in noodles are significantly higher than the other food additives. The obtained results are as follows ; 1) Sodium Carbonate contained Cadmium; 16.73 ug/g and Lead ; 61.55 ug/g. 2) Food Yellow No. 5 contained Cadmium: 1.67ug/g and Lead; 23.46 ug/g. 3) Food Blue No. 1 contained Cadmium; 1. 16 ug/g and Lead; 23.46 ug/g. 4) Food Red Ho. 1 contained Cadmium; 1.91 ug/g and Lead 23.08 ug./g. 5) Alkalies added in noodles contained Cadmium; 6. 11 ug/g and Lead; 53.85 ug/g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.541-555
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• 2016

This study determined the concentrations of lead and cadmium in 18 species of commonly consumed fish and assessed the risk based on provisional tolerable weekly (monthly) intakes [PTW(M)I] % as affected by behavioral characteristics, such as migration and settlement. In the 18 species, the mean concentrations of lead and cadmium were higher in the 11 species of migratory fish (llargehead hairtail Trichiurus lepturus, chub mackerel Scomber japonicus, Pacific saury Cololabis saira, skipjack tuna Katsuwonus pelamis, Pacific cod Gadus macrocephalus, anchovy Engraulis japonicus, Alaska pollack Theragra chalcogramm, brown croaker Miichthys miiuy, Japanese Spanish mackerel Scomberomorus niphonius, yellow croaker Larimichthys polyactis, and Pacific herring Clupea pallasii) than in the seven demersal species (red stingray Dasyatis akajei, brown sole Pleuronectes herzensteini, bastard halibut Paralichthys olivaceus, conger eel Conger myriaster, blackmouth angler Lophiomus setigerus, rockfish Sebastes schlegelii, and filefish Stephanolepis cirrhifer). Based on the mean concentrations, the PTWI % of lead and cadmium in commonly consumed migratory fish were 1.900 and 2.986%, respectively, which were higher than the values for lead and cadmium in the commonly consumed demersal fishes (0.257 and 0.318%, respectively). The estimation of weekly (monthly) intakes and target hazard quotients for the toxic elements lead and cadmium revealed that the commonly consumed migratory and demersal fish do not pose any health risks for consumers.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.325-329
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• 2016

Extracting natural dyes have been widely studied since the needs of eco-friendly and non-toxic natural dyes increased. In this paper, the natural dyes were extracted from sappan wood, gardenia, and mugwort containing brazilein, crocin, and chlorophyll process. After the extraction with variables of pH of solvent and reaction time, the chromaticity of extracted natural dyes was analyzed using quantitative values from brightness and color coordinate (L, a, b) based on the target colors of red, yellow and green. For the case of brazilein and crocin, the cadmium red and cadmium yellow, respectively were extracted. In the case of sappan wood and gardenia, the red pigment under pH 12 (${\Delta}$ = 18.2) and the yellow pigment at pH 9 (${\Delta}$ = 18.4) were extracted respectively. However, the color of extracted chlorophyll from mugwort was different from the target chrome green.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.143-151
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• 2004

The chemical composition of PM$_{2.5}$ was measured at Gosan, Jeju for two weeks each in November 2001 and spring 2002. In the latter part of the measurement period of November 2001, designated as the polluted period in this work, secondarily formed ion components as well as primarily emitted elemental carbon were high. PM$_{2.5}$ mass concentration was also high in this polluted period compared with the yellow sand period, in which daily average of PM $_{10}$ peaked up to 520 $\mu\textrm{g}$/㎥. Increase of major components of anthropogenic origin in the polluted period was not correlated with the variation in sea salt components while increase of crustal components in the yellow sand period was highly correlated with the variation in sea salt components. Trace elements were generally higher in the yellow sand period; however, toxic heavy metals such as zinc, cadmium and lead were the highest in the polluted period.d.d.d.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.23-26
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• 1986

The synthetic conditions of $ ZrSiO_4-Cd(S_xS_{1-x})$ stains from CdS, Se, $SiO_2$ , 4ZrO_2$ and Lif were investigated and the colors were examined. Colors of the stains prepared were yellow orange red pink ruby and violet in relation to both the content of CdS-Se in $ZrSiO_4$ and firing temperature. Colors of these series stains were thermally stabilized probably by the structural stability of zirconium silicate. Furthermore by the result of X-ray diffraction analysis it is assumed that color of the zircon cadmium sulphoselenide $ ZrSiO_4-Cd(S_xS_{1-x})$ stain is developed by neither the coloring ions in $ZrSiO_4$ lattice nor the solid solution of $ZrSiO_4$ and $Cd(S_xS_{1-x})$ but by the small crystals of $Cd(S_xS_{1-x})$ being occluded by the zirconium silicate during sintering process.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2207-2211
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• 2011

Colloidal cadmium telluride (CdTe) quantum dots (QDs) and their nanoparticles have been synthesized by one pot sonochemical reactions under multibubble sonoluminescence (MBSL) conditions, which are quite mild and facile compared to other typical high temperature solution-based methods. For a typical reaction, $CdCl_2$ and tellurium powder with hexadecylamine and trioctylphosphine/trioctylphosphineoxide (TOP/TOPO) as a dispersant were sonicated in toluene solvent at 20 KHz and a power of 220W for 5-40 min at 60 $^{\circ}C$. The sizes of CdTe particles, in a very wide size range from 2 nm-30 ${\mu}m$, were controllable by varying the sonicating and thermal heating conditions. The prepared CdTe QDs show different colors from pale yellow to dark brown and corresponding photoluminescence properties due mainly to the quantum confinement effect. The CdTe nanoparticles of about 20 nm in average were found to have band gap of 1.53 eV, which is the most optimally matched band gap to solar spectrum.