• Food Engineering Progress
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• v.13 no.4
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• pp.251-261
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• 2009

In vitro physiological functions such as jack bean (Canavalia ensiformis) urease inhibitory activity and retarding effect of glucose/bile acid of Aloe vera gel concentrated by the optimized DIS (Dewatering Impregnation & Soaking) process conditions were examined. Urease inhibitory activity of DIS aloes ranged from 84.6 to 94.4%, which was similar to or higher than 86.3% of fresh aloe. Also, urease inhibitory activity of DIS aloes was maintained at initial levels after heat treatment (90$^{\circ}C$, 10 min.) and drying treatment (freeze or hot air drying). Urease inhibition pattern from Lineweaver-Burk plot indicated general non-competitive inhibition, and inhibition constants ($K_{IE}$ and $K_{IES}$) of DIS aloes were 41-149 and 87-163 $\mu$L/mL, respectively. DIS(glucose) and DIS(polyethylene glycol) exhibited the highest retarding effect of glucose and bile acid. Their retarding effects were about 1.6 and 1.8 folds higher than that of fresh aloe after 0.5 and 1 hr of the dialysis, respectively. Conclusively, the above in vitro physiological functions of Aloe vera gel concentrated by DIS process suggested that aloe products treated with DIS would have the potential benefits for protection against Helicobacter pylori and reduction of blood glucose and cholesterol levels.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.168-179
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• 2018

The modified surface of specialty carbon black(SCB) is one of the main technical factors for producing a uniform color and stable dispersion. In this work, the carboxylation or sulfonation process of SCB was used to improve the dispersive properties of hydrophilic solvents such as 1,6-hexanediol and propylene glycol monomethyl ether acetate(PGMEA). The results showed that the color strength of SCB DC2500G changed little with a range of 0.128~0.941(${\Delta}E$) compared to other SCB DC2500G material. In contrast, in the case of SCB EG410, there was a uniform color value with a range of 0.144~0.252(${\Delta}E$). Also, in our experiments, a modified SCB was confirmed by printing ink material as a melt coating paper. It may be possible that the SCB EG410 material can be advantageous as a gravure ink product. Finally, the modified SCB obtained from this research will have a large impact on the industry as a potential material for toners, paint, rubber, fillers, and other carbon black additives.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.11-14
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• 2000

Transparent conducting ITO thin films have been studied and developed for the solar cell substrate or LCD substrate. ITO thin film has been mostly fabricated by high cost sputtering method. In this research, sol-gel method is applied to fabricate ITO thin film at lower cost. The research is focused on the establishment of process condition and development of precursor. Organic sol was made of indium tri-isopropoxide dissolved in ethylene glycol monoethyl ether. The hydrolysis was controled by addition of acetyl acetone. Tin(IV) chloride was added as dopant. Inorganic sol was made of indium acetate dissolve din normal propanol. Spin coating technique was applied to coat ITO on borosilicate glass. The resistivity of ITO thin film was approximately $0.01\Omega{\cdot}cm$ and the transmittance is higher than $90\%$ in a visible range.

• Membrane Journal
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• v.7 no.1
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• pp.39-47
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• 1997

The self-designed membrane system was tested to examine the performance of the hollow fiber type polysulfone ultrafiltration(UF) membrane for the treatment of pure water(the 3rd treated water). The molecular weight cut-off's (MWCO) of the membranes used in this study were 5, 000 and 10, 000, respectively. The recovery rate, the ratio of permeate flow rate to the feed flow rate, increased as the temperature rose. The values of MWCO obtained in this study, using 2, 000 ppm polyethylene glycol and dextran solutions with various molecular weight, showed higher values than those suggested by SKI. Based on the results of the primary experiments, the water of the Gongji-stream, in which water quality is deteriorated by the inflow of domestic wastewater, was selected for the UF membrane test. Biological oxygen demand(BOD), total solids, and turbidity of the treated water had much lower values than those of the source water. Therefore, this study confirmed the possibility of the domestic water treatment using the hollow fiber type UF membrane.

• Journal of Powder Materials
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• v.11 no.6 s.47
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• pp.477-485
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• 2004

Monodispersed flaky silver powder was obtained by controlling the ratios of $H_{2}O_{2}/NH_{3}$ and Agin in a mixed solution of ethylene glycol and ammonia with an addition of PVP. The effects of $NH_{3}/Ag,\; H_{2}O_{2}/Ag\;and\;H_{2}PtCl_{6}/Ag$ on its morphology and size were investigated. In $H_{2}O_{2}-NH_{3}-AgNO_{3}\;system,\;NH_{3}/Ag$ molar ratio was found to be an important reaction factor for the nucleation and crystal growth of Ag powder. The synthesis of flaky powder was optimized at over 6 of $NH_{3}/Ag \;and\;5\;of\;H_{2}O_{2}/Ag\;under\;1.0{\times}10^{-3}\;of\;Pt/Ag.\;Moreover,\;as\;the\; NH_{3}/Ag$ molar ratio increased, the size of precipitates was increased regardless of the amount of Pt. In the absence of $H_{2}PtCI$, the morphology and size of reduced Ag powder were found to be irregular in shape $2-4{\mu}m$ in diameter. However, homogenized fine Ag powder was obtained due to heterogeneous nucleation when $H_{2}PtCI$ used as a cat-alyst, and flaky one was synthesized with the addition of Pt over $1.0{\times}10^{-3}$ of Pt/Ag.

• Journal of Pharmaceutical Investigation
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• v.17 no.3
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• pp.111-126
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• 1987

Methyl methacrylate-butyl methacrylate copolymer (MMBM)-dibutyl phthalate (DBP) films were investigated as a potential topical drug delivery system for the controlled release of nitrofurazone. The kinetic analysis of release data indicated that drug release followed a diffusion-controlled granular matrix model, where the quantity released per unit area is proportional to the square root of time. DBP of several hydrophobic plasticizers selected was found to give the highest release of nitrofurazone. However, hydrophilic plasticizers such as propylene glycol and polyethylene glycol 400 had no controlled release properties and acceptable film formation. The effects of changes in film composition, drug concentration, film thickness, pH of release medium, and temperature on the in vitro release of nitrofurazone were analyzed both theoretically and experimentally. The release rate constant (k') was found to be proportional to DBP content, pH, and the temperature of release medium, but independent of film thickness, and drug concentration in a range of 0.1-0.4% by weight. The linear relationship was found to exist between the log k' and DBP content. The release of nitrofurazone from MMBM-DBP (8:2) films was found to be an energy-linked process. Two energy terms were calculated ; the activation energy for matrix diffusion was 13.45 kcal/mole, and the heat of drug crystal solvation was 27.26-29.34 kcal/mole. Observation of scanning electron micrographs and microscopic photographs showed that the incorporation of DBP in films increased markedly the particle size of nitrofurazone dispersed in the film matrix, comparing with the fine dispersion of nitrofurazone in pure MMBM film alone.

• Agricultural and Biosystems Engineering
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• v.6 no.1
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• pp.27-33
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• 2005

Soy protein meat analog was produced using a twin-screw extruder attached with a cooling die. Heat transfer analysis was performed for cooling dies with various die sizes at the four different moisture contents of feed during extrusion process. The experimental design consisted of two cooling die widths (30 and 60 mm), three cooling die lengths (100, 200, and 300 mm), four product moisture contents (71.2, 67.0, 61.6 and 55.8%), and water and water plus ethylene glycol as cooling material. When water was used as cooling medium, the values of equivalent overall heat transfer coefficient $(U_e)$ for each die width of 30 and 60 mm were in the range of 187.0 - 341.4 and $358.5-191.6W/m^2^{\circ}C$ depending on the size of die length. Convective heat transfer coefficients between cooling water and inside die wall of cooling channel $(h_c)$ for both die widths of 30 and 60 mm were 588.5, 416.1, and $339.8W/m^2^{\circ}C$ for each die length of 100, 200, and 300 mm. Convective heat transfer coefficients between product and inside die wall of product channel $(h_p)$ for each die width of 30 and 60 mm were in the range of $434.6-888.1W/m^2^{\circ}C$ and $460.7-1014.5W/m^2^{\circ}C$ depending on the size of die length. When water plus ethylene glycol was used as cooling medium, the values of $U_e$ were in the range of $143.9-319.6W/m^2^{\circ}C$ and $177.8-332.7W/m^2^{\circ}C$ for each die width of 30 and 60 mm depending on the size of die length.

• Journal of Pharmaceutical Investigation
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• v.6 no.3
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• pp.48-57
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• 1976

An enhancement in the dissolution rate of the drug should facilitate its GI absorption if the absorption process is dissolution rate limited. One of the need for the techniques that can potentially enhance the dissolution rate and extent of absorption of hydrophobic drugs is the formation of coprecipitates with pharmacologically inert, polymeric materials. The physicochemical modification offers the advantage of possibly enabling one to administer the drug orally in a form from which it is most available for GI absorption. Several $investigation^{1-15)}$ demonstrated that the formation of solid dispersions or coprecipitates of relatively water-insoluble drugs with various pharmacologically inert carriers can increase singnificantly their in vitro dissolution rates. However, little information is available in the literature related to the dissolution rate patterns of furosemide, a water-insoluble diurectices, with respect to the sort of copolymer and the ratio of coprecipitates as a function of time, respectively. The purpose of the present investigation was to ascertain, the general applicability of the copolymers to use fore more fast, enhanced dissolution techniques of furosemide. To accomplish the need for enhancement in the dissolution rate of furosemide, varying ratio coprecipitates with different water-soluble polymers, such as polyvinylpyrrolidone (PVP), polyethylene glycol 4000(PEG 4000), and polyethylene glycol 6000 (PEG 6000), were quantitatively studied by comparing their dissolution characteristics of furosemide. The dissolution patterns of pure furosemide, varying ratio furosemide-PVP coprecipitates, (1:2, 1:5, and 1:9(w/w)), furosemide-PEG 4000 coprecipitates (1:4, 1:9, and 1:19(w/w), furosemide-PEG 6000 coprecipitates(1:4, 1:9, and 1:19(w/w)), and the same ratio physical mixtures, respectively, were compared by the amount dissolved as a function of time.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.228-238
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• 2005

Purpose: Several cryoprotectants are in use to help the survival of cells during cryopreservation of bone in maxillofacial region. Among them, $Me_2SO$(dimethyl sulfoxide), EG(ethylene glycol), sucrose were used for experimentally created defects with accompanying cryopreserved bone graft in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Materials and methods: Nine rabbits were used as experimental animals. Surgical defects were created on the distal femoral heads and mesial tibial heads of each animal using trephine drill(5mm diameter and 5mm length). The harvested bones were cryopreserved in $-80^{\circ}C$ refrigerator for one week. The defects were filled with cryopreserved bone with cryoprotectants as experimental groups and cryopreserved bone without cryoprotectant as control. Then, the animals were sacrificed at 1, 2, and 3 weeks after surgery. With Goldner's modified Masson trichrome staining and semiautomatic image analysis system, we observed the change of the cells and bone formation. Results: After bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the control were somewhat weaker than that of the experiments. Especially $Me_2SO$+sucrose group was the best in bone formation and bone remodeling. $Me_2SO$ group was more than that of EG group in bone fomation. Sucrose seems to be helpful in survival of the bone cell. Histologic findings showed superior bony quantity and quality in experimental groups than that in control. Conclusions: The data from this study provides the basis for future studies for evaluating the effect of cryoprotectants in the cryopreservation of bone and clinical study for predictable use of these agents.

• Analytical Science and Technology
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• v.17 no.2
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• pp.173-179
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• 2004

The $BaTiO_3$ powders and thin films were prepared by an alkoxide modified sol-gel process (polymerization-complex route) using ethylene glycol. The stable starting (Ba-Ti)-mixed metal organic sol was made by addition of acetylacetone. The $BaTiO_3$ powders, which had a particle size of 40~77 nm, were crystallized from an amorphous to a tetragonal phase on annealing at 700 and $1100^{\circ}C$ for 1 h. From FT-IR, solid-state $^{13}C$ CP/MAS NMR spectroscopy and X-ray diffractometry, the trace of the Ba-Ti-oxycarbonate phase first appeared at $400^{\circ}C$. Hydrolyzed sol was spin coated on a quartz wafer at 3500 rpm for 60 s and pyrolyzed at $1100^{\circ}C$ for 1 h. After heat treatment, the coated layer became dense and smooth.