• Journal of the Korean Applied Science and Technology
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• v.26 no.4
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• pp.473-482
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• 2009

Titanium dioxide particles are used as cosmetics, pigments, photocatalysts, adsorbents, catalytic supports, and sensors. The $TiO_2$ particles were prepared by the precipitation in TTIP/Solvent mixtures and calcined at different temperatures. The resulting materials were characterized by XRD and SEM testing techniques. The $TiO_2$ particles phase composition was determined by XRD ranging from amorphous to crystalline anatase and rutile largely proportional to the calcination temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.670-673
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• 2002

Powder synthesis using the alkoxy precursor technique exhibits processing flexibility not available in traditional high temperature solid-state reaction. With proper process control, impurities can be reduced to very low levels. The major distinction of the present work lies in the method of accomplishing the hydrolysis reaction. In the present case, water is not added to the system. Instead the metal alkoxide/alcohol solution is heated to a temperature at which water is formed through dehydration of the alcohol solvent, causing precipitation of the corresponding metal oxide (hydroxide). The present method provides a means of producing amorphous alumina.

• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.120-124
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• 1998

For the purpose of evaluating protective components against alcohol-induced toxicity, the active components enhancing alcohol metabolism was pursued from water soluble fraction by ethanol precipitation and DEAE-cellulose chromatographic technique. As a result, various high molecular weight fractions from Aloe vera and Aloe arborescens, on a single oral administration in rats were found to cause a significant decrease in the blood ethanol concentration as well as enhancement of liver cytosolic ADH and ALDH activities and among which, a strong acidic high molecular weight fraction was demonstrated to exhibit the most potent enhancing activity on ethanol metabolism.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.288-295
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• 2006

This study was conducted to examine the possibility of improvement effect in suppression of precipitation and nasty smell creation in Takju mash. First of all, gum shown to be lowest precipitation velocity was selected and this was applied to the fermentation of Takju mash for comparing with the control in terms of fermentation aspects and various qualities of Takju mash. Precipitation amount and precipitation velocity of suspension in Takju mash added with carrageenan was shown to be the lowest than that of others. Compared with the control, alcohol was highly generated in Takju mash added with carrageenan, especially between two and four days. Total acidity was shown to be highly increased until 2 days in Takju mash and thereafter to be slightly increased. Takju mash added with carrageenan was shown to be lower on the second stage than the control. Fusel oil produced from mash added with carrageenan was 0.046${\sim}$0.113${\mu}$l/ml and mash added with carrageenan generated less fusel oil than the control by 1.6${\sim}$3.2 fold. Yeast growth on the mash added with carrageenan was revealed to be helpful during fermentation periods. In general, sensory characteristics of Takju mash were shown to be more superior in mash added with carrageenan than in other samples. While nasty smell produced from a sample without gums was perceived after 2 days of Takju mash storage, nasty smell of Takju mash added with carrageenan was recognized after 6 days during storage. In conclusion, precipitation of suspension and nasty smell production in Takju mash were found to be suppressed by addition of carrageenan during Takju fermentation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.204-211
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• 2023

This study investigated the physicochemical properties and palatability-enhancing effects of the alcohol precipitate, in the enzymatic extracts of Sargassum confusum C. Agardh (SC), obsained using the crude enzyme of Shewanella oneidensis PKA 1008. We analyzed the oligosaccharides recovered from the alcohol precipitate using a thin-layer chromatography for SC-degrading extracts, pH, color, reducing sugar, and viscosity. Thin-layer chromatography showed that after treating with the crude enzyme for 60 h, the polysaccharides were degraded into tetramers, dimers, and trimers and pH increased in the alcohol precipitate (EtOH Sedi). In terms of color, the redness and yellowness of alcohol precipitate/supernatant (EtOH Sedi+Super) and the brightness of EtOH Sedi were the highest among enzyme treated for 0 h and 60 h, EtOH Sedi, and EtOH Sedi+Super. In the reducing sugar analysis, EtOH Sedi showed the lowest value of 13.63 ㎍/mL, and the lowest viscosity of 1.13. In terms of the sensory evaluation, EtOH Sedi+Super showed the highest value with respect to the overall preference. These results suggest that the crude enzyme of S. oneidensis PKA 1008 is effective at degrading polysaccharides, and its recovery increases the palatability of the alcohol precipitate.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.951-956
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• 2001

A 28-kDa extracellular lipase (pI 8.7) was purified to homogeneity from the culture supernatant of Trichosporon sp. Y- 11 by mmonium sulfate precipitation, DEAE-Sephadex A-50, Bio-Gel P-30, CM- Sephadex C-50, and Bio-Gel P- 10 chromatographies. The purified enzyme exhibited a specific activity of $2,741{\;}{\mu}mol/min/mg$ based on the hydrolysis of triolein, and the optimal hydrolysis activity was dentified at pH 8.0 and $40^{\circ}C$. The enzyme activity was inhibited by $Ag^+$ and enhanced by $Fe^{2+}$, $Fe^{3+}$, $Mg^{2+}$, $Mn^{2+}$, and $Li^{+}$. The enzyme activity exhibited for the hydrolysis of both tributyrin and trilinolein. The ester synthesis of unsaturated fatty acids with various alcohols catalyzed by the purified lipase in a nonaqueous medium or microaqueous system was also investigated. The esterification activity of the lipase increased with an increase of the carbon chain length in the alcohol. The synthesis rate of linoleic acid and oleyl alcohol was the highest with an optimal temperature and pH of $40^{\circ}C$ and 8.0, respectively. The water content and agitation also affected the esterification activity of the lipase.

• Clean Technology
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• v.12 no.2
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• pp.101-106
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• 2006

HT-$LiCoO_2$ powders were synthesized from hydroxide precursors in this study. The cobalt hydroxide compounds with hydrotalcite-like(${\alpha}$-phase) and/or brucite-like(${\beta}$-phase) structures as a component of the precursor were prepared in various PH conditions using precipitation method. It was found that various phase and compositions of cobalt hydroxides could be tailor-prepared via a careful control of preparation parameters such as the concentration ratio of $[OH^-]/[CO^{2+}]$ and aging time. The hydroxides $Co(OH)_2$ and LiOH were mixed with aqueous methyl-alcohol. The precursor of a HT-$LiCoO_2$ was synthesized via subsequent processes including evaporation, drying and aging. The transformation of tailor-made ${\beta}$-phase $Co(OH)_2$ to CoOOH and formation of solid solution in the precursor were achieved during aging. These results cause HT-$LiCoO_2$ to be synthesized at low temperature($600^{\circ}C$ ) for a short time(10min).

• Journal of Powder Materials
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• v.10 no.5
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• pp.310-317
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• 2003

Two-component ceramic (alumina-zirconia) composites were fabricated by a soft-solution process in which polyethylene glycol (PEG) was used as a polymeric carrier. Metal salts and PEG were dissolved in ethyl alcohol without any precipitation in 1:1 volume ratio of alumina and zirconia. In the non-aqueous system, the flammable solvent made explosive, exothermic reaction during drying process. The reaction resulted in formation of volume expanded, porous precursor powders by a vigorous decomposition of organic components in the precursor sol. The PEG content affected the grain size of sintered composites as well as the morphology of precursor powders. The difference of microstructure in sintered composite was attribute to the solubility and homogeneity of metal cations in precursor sol. At the optimum amount of the PEG polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. It made less agglomerated particles in the precursor sol and affected on uniform grain size in sintered composite.

• Journal of the Korean Graphic Arts Communication Society
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• v.20 no.1
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• pp.102-112
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• 2002

Cathode ray tubes (CRT) are the most common electronic display in use in information technology. The CRT consists of an electron gun, electrostatic or magnetic fields to direct the electron beam, and a phosphor screen. When the electron beam strikes the phosphor screen, the phosphor generates light. The phosphor screen has formed by precipitation method, electro-forming and centrifuge method. The high quality product was achieved by electro-forming or centrifuge method. Now applying method is electro-forming used with phosphor and Eh(isopropyl alcohol). Now applying method has been much consumption of raw-material, dirty working environment, dangerous fire and require of high cost. New method to form phosphor surface of monochrome is required to improve this matter. This study was developed novel method to form the phosphor surface by heat-transfer method. This method have advantages of simple process, automatization, clean environment, saving raw material and saving running-cost.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.379-382
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• 2004

Entomopathogenic nematodes are used for insect control. Herein, an extracellular protease was partially purified from a culture supernatant of Xenorhabdus nematophilus, a symbiotic bacterium of an entomopathogenic nematode, Steinernema glaseri: using precipitation with $80\%$ v/v isopropyl alcohol followed by gel permeation chromatography with a packed Sephacryl S-300 HR media. The partially purified protease exhibited maximal activity at pH 7 in the presence of 1 mM $CaCl_2$. The protease was identified as a metallo-protease based on the inhibition of its activity by the metal chelating agent, EDTA.