• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1158-1164
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• 1998

Aluminium sulfate solution was prepared by sulfuric acid treatment from gibbsite. Aluminium sulfate hydrate [$Al_2(SO_4)_3$ · $nH_2O$] was precipitated from aluminium sulfate solution by adding it into ethylalcohol. From XRD analysis as-prepared $Al_2(SO_4)_3$ · $nH_2O$ was confirmed to have mixed-crystalization water(n=18, 16, 12, 6). The average water of crystalization calculated from thermogravimetry(TG) was 14.7. Aluminium sulfate hydrate [$Al_2(SO_4)_3$ · $nH_2O$] was thermally decomposed and converted to $Al_2(SO_4)_3$ at $800^{\circ}C$, $\gamma-Al_2O_3$ at $900-1000^{\circ}C$, and $\alpha-Al_2O_3$ at $1200^{\circ}C$. Ni-doped $\gamma-Al_2O_3$, was synthesized from the slurry of as-prepared $\gamma-Al_2O_3$, with the ratio of [Ni]/[Al]=0.5. The reaction conditions of synthesis were determined as initial pH 9.0 and temperature $80^{\circ}C$ The basicity(pH) of slurry was controlled by using urea and $NH_4OH$ solution. Urea was also used for deposition-precipitation. For determining termination of reaction, the data acquisition was performed by oxidation reduction potential(ORP), conductivity and pH value in the process of reaction. Termination of the reaction was decided by observing the reaction steps and rapid decrease in conductivity. On the other hand, BET(Brunauer, Emmett and Teller) and thermal diffusity of Ni- doped $\gamma-Al_2O_3$, with various content of Ni were measured and compared. Thermal stability of Ni- doped $\gamma-Al_2O_3$ at $1250^{\circ}C$ was confirmed from BET and XRD analysis. The surface state of Ni-doped $\gamma-Al_2O_3$ was investigated by X-ray photoelectron spectroscopy(XPS). The binding energy at $Ni2P_{3/2}$ increased with increasing the formation of $NiAl_2O_4$ phase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.289-293
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• 2005

Nowadays there are many sun protection cosmetics including organic or inorganic UV filter as an active ingredient. Chemically stable inorganic sunsEreen agents, usually metal oxides, we widely employed in high SPF products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as pigments for a long period of cosmetic history. With the development of micronization techniques, it becomes possible to incorporate titanium dioxide in sunscreen formulations without whitening effect and it becomes an important research topic. However, there are very few works related to quantitations of titanium dioxide in sunscreen products. In this research, we analyzed amounts of titanium dioxide in sunscreen cosmetics by adapting redof titration, reduction of Ti(IV) to Ti(III) and reoxidation to Ti(IV). After calcification of other organic ingredients of cosmetics, titanium dioxide is dissolved by hot sulfuric acid. The dissolved Ti(IV) is reduced to the Ti(III) by adding aluminum metals. The reduced Ti(III) is titrated against a standard oxidizing agent, Fe(III) (ammonium iron(III) sulfate), with potassium thiocyanate as an indicator In order to test accuracy and applicability of the proposed method, we analyzed the amounts of titanium dioxide in four types of sunscreen cosmetics, such as cream, make-up base, foundation and powder, after adding known amounts of titanium dioxide $(1{\sim}25w/w%)$. The percent recoveries of the titanium dioxide in four types of formulations were in the range between 96 and 105%. We also analyzed 7 commercial cosmetic products labeled titanium dioxide as an ingredient and compared the results with those of obtained from ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry), one of the most powerful atomic analysis techniques. The results showed that the titrated amounts were well coincided with the analyzed amounts of titanium dioxide by ICP-AES. Although instrumental analytical methods, ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) and ICP-AES, are the best for the analysis of titanium, it is hard to adopt because of their high prices for small cosmetic companies. It was found that the volumetric method presented here gat e quantitative and reliable results with routine lab-wares and chemicals.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.81-89
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• 2019

The major problem encountered during the storage of pig slurry (PS) is the release of huge amounts of greenhouse gases (GHGs), which are dominated by methane ($CH_4$). To reduce this, concentrated sulfuric acid has been used as an additive to control the pH of pig slurry to 5.0-6.0. However, other low-risk substitutes have been developed due to some limitations to its use, such as corrosiveness, and hazards to animal and human health. In this study, sugar addition was proposed as an eco-friendly approach for limiting $CH_4$ emission from PS during storage. The pH of PS has been reduced from $7.1{\pm}0.1$ (control) to $5.8{\pm}0.1$, $4.6{\pm}0.1$, $4.4{\pm}0.1$, $4.1{\pm}0.1$, and $4.0{\pm}0.1$, by the addition of 10, 20, 30, 40, and 50 g sugar/L, respectively. Lactate, acetate, and propionate were detected as the dominant organic acids and at sugar concentration above 20 g/L, lactate concentration represented 42-72% (COD basis) of total organic acids. For 40 d of storage, $20.6{\pm}2.3kg\;CO_2\;eq./ton\;PS$ was emitted in the control. Such emission, however, was found to be reduced to $8.7{\pm}0.4$ and $0.4{\pm}0.1kg\;CO_2\;eq./ton\;PS$ at 10 and 20 g/L, respectively. Small amount of $CH_4$ from PS at 10 g/L was emitted until 30 d of storage, while for rest of storage period, it has increased to $8.7{\pm}0.4kg\;CO_2\;eq./ton\;PS$ ( 40% of the control) when methanogens have recovered by increasing pH to 7.0. By the end of storage, VS and COD removal in the control reached 24% and 27%, while their ranges reached 15-4% and 12-17% in the sugar added experiments, respectively. It was found that more than 90% of COD removal was done by aerobic biological process.