• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.360-368
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• 2022

PURPOSE. This study assessed the physical and mechanical properties of interim crown materials fabricated using various digital techniques after accelerated aging. MATERIALS AND METHODS. Three groups of interim dental restorative materials (N = 20) were tested. The first group (CO) was fabricated using a conventional manual method. The second group (ML) was prepared from prefabricated resin blocks for the milling method and cut into specimen sizes using a cutting disc. The third group (3D) was additively manufactured using a digital light-processing (DLP) 3D printer. Aging acceleration treatments using toothbrushing and thermocycling simulators were applied to half of the specimens corresponding to three years of usage in the oral environment (N = 10). Surface roughness (Ra), Vickers microhardness, 3-point bending, sorption, and solubility tests were performed. A 2-way analysis of variance (ANOVA) and Fisher's multiple comparison test were used to compare the results among the groups. RESULTS. The mean surface roughness (Ra) of the resin after accelerated aging was significantly higher in the CO and ML groups than that before aging, but not in the 3D group. All groups showed reduced hardness after accelerated aging. The flexural strength values were highest in the 3D group, followed by the ML and CO groups after accelerated aging. Accelerated aging significantly reduced water sorption in the ML group. CONCLUSION. According to the tested material and 3D printer type, both 3D-printed and milled interim restoration resins showed higher flexural strength and modulus, and lower surface roughness than those prepared by the conventional method after accelerated aging.

• Journal of Soil and Groundwater Environment
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• v.25 no.2
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• pp.9-15
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• 2020

This study was conducted to investigate the in situ formation of amorphous Fe oxides as a stabilization technology in As-contaminated soil. After addition of ferric nitrate and the neutralizing agent, most of extractable fractions of As in soil (i.e., SO₄^2- and PO₄^3--extractable As) was converted into As bound to amorphous Fe oxides. In addition, results of solubility bioavailability research consortium (SBRC) test indicated that a significant amount of As in untreated soil changed to a non-bioaccessible form after stabilization. The reason was attributed to the newly formed amorphous Fe oxides in the stabilized soil, which was confirmed by linear combination of fitting (LCF) using X-ray absorption spectroscopy (XAS) analysis. Interestingly, after five months of aging of the stabilized soil, ferrihydrite and schwertmannite newly formed in the soil were transformed to crystalline Fe oxides such as goethite, and further decrease in SBRC extractable fraction of As was observed. The results suggest that co-precipitated As with amorphous Fe oxides can be further immobilized with time, due to the crystallization of amorphous Fe oxides.

• KSBB Journal
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• v.22 no.5
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• pp.328-335
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• 2007

In this work ursolic acid (UA), a poorly water-soluble compound, was inclusion complexed with 2-hydroxypropyl-$\beta$-cyclodextrin (HP-$\beta$-CD) by various methods such as kneading, solvent evaporation and two types of supercritical fluid processes. The solubility and characteristics of these UA/HP-$\beta$-CD complexes were investigated by scanning electron microscopy, x-ray diffraction and HPLC. The water solubilities of the two complexes obtained from solvent evaporation and ASES processes were observed to increase up to 6$\sim$240 folds and 12$\sim$56 folds, respectively, compared with that of unprocessed UA. The stability of UA/HP-$\beta$-CD complex samples in cosmetic formulations was examined at various temperatures for one month. The UA/HP-$\beta$-CD complex prepared by solvent evaporation was found to be most stable among all the cosmetic formulations tested in our experiments.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.49-55
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• 1970

In preparation of textured soybean protein, drying process of the isolated protein affected its gelling property and other related characteristics such as water holding capacity and viscosity. In model systems, denaturation of the protein, as determined in terms of nitrogen solubility index (NSI), was appeared to be a parameter of the gel strength of soybean protein isolate. The gel strength was maximum when the protein was denatured properly during drying process of which the NSI was 43 in this experiment and decreased at either the higher or the lower NSI. It indicated that proper denaturation of the protein during drying operation is advantagous for the preparation of textured soybean protein but not neccesary to make highly undenatured one.

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.55-67
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• 1986

Inclusion complexation of tiaprofenic acid (TPA) with cyclodextrins $({\alpha}-,\;{\beta}-,\;{\gamma}-CyDs)$ in aqueous solution and in solid phase was investigated by solubility method, measurement of partition coefficient, ultra-violet, circular dichroism, infrared spectroscopies, powder X-ray diffractometry and differential scanning calorimetry. Investigations were made to prepare inclusion complexes of TPA with ${\beta}-CyD$ in solid powdered form by coprecipitation, freeze-drying, spray-drying and co-pulverization methods. The coprecipitation, freeze-drying and spray-drying methods were successful in obtaining inclusion complexes. The results showed that the latter two methods might be originally superior to the former in obtaining powdered inclusion completes. Especially, it was shown by powder X-ray diffractometry that spray-dried ${\beta}-CyD$ alone, TPA-spray-dried ${\beta}-CyD$ physical mixture, and spray-dried $TPA-{\beta}-CyD$ complex were amorphous. The dissolution behaviours of $TPA-{\beta}-CyD$ systems prepared by above four methods were compared with those of TPA alone and $TPA-{\beta}-CyD$ physical mixture, and the rates of dissolution of TPA in pH 1.2 buffer were greatly enhanced by inclusion complexation and copulverization.

• Journal of Life Science
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• v.19 no.5
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• pp.553-560
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• 2009

Based on $P_{1/2}$ values, relative affinities of alginate, polyguluronate, and polymannuronate for metal ions are, in order, as follows; 1) seaweed alginate: $Cu^{2+}$ > $Cd^{2+}$ > $Pb^{2+}$ > $Fe^{3+}$ >> $Zn^{2+}$ > $Sr^{2+}$ > $Ca^{2+}$ > $Co^{2+}$ >> $Cr^{6+}$ > $Mn^{2+}$ >> $Hg^{2+}$, $Mg^{2+}$, $Rb^+$, 2) polyguluronate: $Cd^{2+}$ > $Cu^{2+}$ > $Pb^{2+}$ > $Fe^{3+}$ >> $Ca^{2+}$ > $Sr^{2+}$, $Zn^{2+}$, $Co^{2+}$ >> $Mn^{2+}$ > $Cr^{6+}$ >> $Hg^{2+}$, $Mg^{2+}$, $Rb^+$, and 3) polymannuronate: $Cd^{2+}$, $Cu^{2+}$ > $Fe^{3+}$ > $Pb^{2+}$ > $Ca^{2+}$ > $Zn^{2+}$ > $Sr^{2+}$ > $Co^{2+}$ > $Cr^{6+}$ >> $Mn^{2+}$ >> $Hg^{2+}$, $Mg^{2+}$, $Rb^+$. Amounts of the metal ions, $Cd^{2+}$, $Cu^{2+}$, $Fe^{3+}$, $Pb^{2+}$, and $Zn^{2+}$, bound to 1 g of seaweed alginate, were measured as $363.5{\pm}45.0$, $226.3{\pm}9.2$, $1,299.4{\pm}$81.3, 500.7${\pm}$27.7, and 165.9${\pm}$11.4 mg, respectively. Amounts of the metal ions, $Cd^{2+}$, $Cu^{2+}$, $Fe^{3+}$, $Pb^{2+}$, and $Zn^{2+}$, bound to 1g of polyguluronate, were 354.5${\pm}$26.5, 177.6${\pm}$8.7, 1,288.6${\pm}$60.1, 424.0${\pm}$7.4, and 140.2${\pm}$28.5 mg, respectively, whereas those bound to 1 g of polymannuronate were 329.0${\pm}$10.3, 206.9${\pm}$1.9, 1,635.6${\pm}$11.1, 419.8${\pm}$12.6, and 251.0${\pm}$49.1 mg, respectively. Due to its higher solubility than alginate and higher affinity for metal ions than polyguluronate, polymannuronate can be used for bioremediation or biosorption of toxic and/or noble metal ions.

• Food Science and Preservation
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• v.12 no.5
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• pp.460-464
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• 2005

In order to produce functional soy hydrolysates, we investigated the characteristics of soy hydrolysates prepared with 4 kinds of commercial proteases. The yield was high in protease(B), in which 43.2% soy flour and 61.6% SPI were obtained. The solubility and the contents of total phenolic compound were greatly increased by the treatment of protease(B) along with protease(C). The calcium intolerance was improved after the protease(B) treatment in soy flour or Soybean Protein isolate (SPI). Consideration for the physicochemical characteristics including yield, protease(B) has potential application for the production of soy hydrolysates. After the protease treatment, the beany flavor of soy flour became weak and the bitter taste was strong in both soy flour and SPI. However, there was no difference of beany flavor and bitter taste among delete protease hydrolysates. Nevertheless, further modifications and improvements to the sensory characteristics would be required for the development of a range of products with the hydrolysate.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.288-294
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• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.233-239
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• 2010

Supercritical carbondioxide is very effective in removing oils from a variety of seed matrices, devoid of any appreciable amount of phospholipid content. However, the limited solubility of phosphalipids in supercritical carbondioxide leaves behind a potentially valuable by-product in spent seed matrix. Any phospholipid extraction process from the spent matrix must maintain the structure and the quality of phospholipids and must be compatible with the end use of the seed protein meal an animal feed or for human consumption. An initial supercritical carbondioxide extraction of soybean flakes was performed at 32 MPa and $80^{\circ}C$ to extract the oils, leaving the phospholipids in the deflatted soybean flakes, A second step was performed on the defatted soybean flake using $X_{eth}$=0.10, Varying the pressure from 175 MPa to 70.6 MPa and temperature from $60^{\circ}C$ to $80^{\circ}C$. For all supercritical carbon dioxide/ethanol mixture extractions, a fraction rich in phospholipids was obtained. The fractions extracted from defatted soybean flakes were dried and them redissolved in chloroform before HPLC-ELSD analysis. Quantitative and qualitative analysis of phospholipids on soybean seeds, defatted soybean flake, and different extracted phospholipid fractions was carried out, to ascertain the effect of extraction pressure and temperature.

• Clean Technology
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• v.25 no.3
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• pp.245-255
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• 2019

Pressurized oxy-fuel combustion is a promising technology for $CO_2$ capture with a benefit of improving power plant efficiency compared with atmospheric oxy-fuel combustion. Prior to $CO_2$ compression in this process, a flue gas condenser (FGC) is used to remove $H_2O$ while recovering the latent heat. At the same time, the FGC has a potential for high-efficiency removal of $SO_x$ and $NO_x$ by exploiting their good solubility in water. In this study, experiments were carried out in a lab-scale, direct contact FGC under different pressures varying between 1 and 20 bar to evaluate the removal efficiency of $SO_2$ and $NO_x$ for individual gases and their mixture. In the tests for individual gases, 20% and 76% of $NO_x$ was removed at 1 bar and 10 bar, respectively. Even higher removal efficiencies were achieved for $SO_2$, and also these were maintained for longer as the pressure increased. In the tests for $SO_2$ and $NO_x$ mixture, the removal efficiency of $NO_x$ increased from 13% at 1 bar to 56% at 20 bar because of higher solubility at elevated pressures. $SO_2$ in the mixture was initially dissolved almost completely and then increased by 1,219 ppm at 1 bar and by 165 ppm at 20 bar. Overall, the removal efficiency of $SO_2$ and $NO_x$ was increased at elevated pressures, but it was lower in the mixture compared with individual gases at identical conditions because of a lower pH and associated chemical reactions in water.