• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.60-71
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• 2014

Cable-stayed bridge, which is one of the representative long-spanned bridge, needs prompt maintenances when a stay cable is damaged because it may cause structural failure of the entire bridge. Many researches are being conducted to develop abnormal behavior detection algorithms for the purpose of shortening the reaction time after the occurrence of structural damage. To improve the accuracy of the damage detection algorithm, ample observation data from various kinds of damage responses is needed. However, it is difficult to measure an abnormal response by damaging an existing bridge, numerical simulation can be an effective alternative. In most previous studies, which simulate the damage responses of a cable-stayed bridge, the damages has been considered as a load variation without regard to its stiffness variation. The analyses of using these simplification could not calculate exact responses of damaged structure, though it may reserve a sufficient accuracy for the purpose of bridge design. This study suggests Gradual Bilinear Method (GBM) which simulate the damage responses of cable-stayed bridge considering the stiffness and mass variation, and develops an analysis program. The developed program is verified from the responses of a simple model. The responses of a existing cable-stayed bridge model are analyzed with respect to the fracture delay time and damage ratio. The results of this study can be used to develop and verify the highly accurate abnormal behavior detection algorithm for safety management of architecture/large structures.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.300-306
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• 1989

Physico-chemical changes caused by salting Korean radish cubes (for Kakdugi) with sodium chloride solution were investigated. Two-centimter cubes of Korean radish were soaked in saline solution of 5, 10, 15, 20 and 25 percent concentration. Optimum salinity, 3% as determined by taste, was reached in six hours at 5% strength, two hours in 10%, one hour at 15% and within one hour at concentration of 15% plus. Radish cubes salted in 5, 10. 15, 20 and 25% sodium chloride solution in a cube/solution weight ratio of 1:1 decreased in volume from 7.6 to 11.2% after one hour, and from 11.2 to 17.9% after six hours. Decrease in moisture content was from 83.0 to 75.9% in one hour and from 74.5 to 68.5% after six hours. $Potassium\;ion(K^+)$, $calcium\;ion(Ca^{2+})$ and $magnesium\;ion(Mg^{2+})$ content was significantly decreased by salting, but $sodium\;ion(Na^+)$ content greatly increased. In addition, salting caused firmness of the cubes to decrease, and cell shapes to shrink by plasmolysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.1058-1063
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• 2015

The feasibility of incorporating black sesame powder (BSP) as a value-added food ingredient into bakery products was investigated using a cookie model system. BSP was incorporated into cookies at different content: 0%, 2%, 4%, 6%, and 8% (w/w) based on the total weight of wheat flour. The spread ratio and loss rate of cookies increased significantly with increasing levels of BSP (P<0.05). All color characteristics, including lightness ($L^*$), redness ($a^*$), and yellowness ($b^*$), decreased with a higher amount of BSP. Use of BSP significantly reduced the hardness of cookies (P<0.05), but no significant differences were found between the control and 2%, 4%, and 6% samples (P>0.05). 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities increased significantly (P<0.05). The consumer acceptance test indicated that addition of BSP up to 4% had a favorable effect on consumer preferences. Overall, cookies containing 4% BSP will add the advantage of the functional properties of BSP maintaining the consumer acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1111-1117
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• 2009

Effect of Rubus coreanum Miquel and Opuntia ficus-indica var. saboten in combination with chicken breast and wheat gluten on functional properties and physicochemical characteristics during processing of cooked noodles were investigated. These studies were carried out to investigate functional properties of Rubus coreanum Miquel and Opuntia ficus-indica var. saboten by the antioxidant ability. Antioxidant activities were evaluated by electron donating, xanthine oxidase inhibition rate and contents of total polyphenols. Overall, the antioxidant activities of hot water extracts were a little higher than those of ethanol extracts. Also, the antioxidant abilities at the concentration of 1,000 ppm in hot water extracts were higher than those of ethanol extracts by the determination of total polyphenol content and DPPH, which showed 150.25 mg% in extracts of Rubus coreanum Miquel and showed 69.36% in extracts of Opuntia ficus-indica var. saboten. The effects on processing characteristics of cooked noodles were investigated in combination with transglutaminase (TGase), plant extracts, wheat gluten and chicken breast. Cooking time was very short as 340 second in CB (cooked breast), compared to other treatments. In contrast, NCB (non cooked breast) took a longer time as 779 second. Also, CB was higher than NCB, which showed 146.3% in CB and 61.5% in NCB in water absorption ratio during cooking of noodles. Tubidity of soup was the lowest at 0.240 in NCBT (non cooked breast transglutaminase), which means the lowest loss of solid in noodle during cooking. In case of treatment of TGase, overall texture properties were higher than other samples in hardness, cohesivness, springness and gumminess. In sensory evaluations, cooked noodles treated with TGase showed a higher percentage of overall acceptability than other treatments.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.381-388
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• 1974

When mixture of p-phenylenediamine (PPD) and m-aminophenol (MAP) were reacted with formaldehyde (F) varying their amounts under $N_2$ stream at the temperature of -5∼0$^{\circ}$, addition condensation reaction occurred and brown colored resins(in some cases orange colored) were formed immediately. All resins thus formed were insoluble in most ordinary organic solvents and did not melt up to 300$^{\circ}$. When the resins were treated with dilute(7 %) aqueous sodium hydroxide solution, the adsorptivity of methylene blue on them showed marked improvement reaching as much as 80 mg of methylene blue on 1 g of the resin. On the other hand, in the case of bromophenol blue, its amount of adsorption appeared 250 mg per 1 g of the resin. The TGA under $N_2$ atmosphere indicated that the resin formed in molar ratio of 1 : 3 : 8 (PPD : MAP : F) showed the best heat-resistant property among others. About 40 % weight loss was observed for this resin at 900$^{\circ}$ with heating rate of 2$^{\circ}$ per minute.

• Journal of the Korean Chemical Society
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• v.10 no.1
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• pp.32-42
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• 1966

The electrolysis of tungstic oxide dissolved in the bath of calcium chloride and calcium oxide was studied to produce metallic tungsten using carbon as anode and iron as cathode in the temperature range of 900^{\circ}$ to $1200^{\circ}C$. The binary phase diagrams $CaCl_2$-CaO and $CaCl_2-CaWO_4$ systems were constructed to determine the suitability of bath composition and the range of temperatures for the electrolysis. As $WO_3$ reacted with $CaCl_2$ to form oxychloride in the fused salt, the addition of the proper amount of CaO was necessary to avoid the loss of $WO_3$. The optimum compositions of fused bath were $CaCl_2$ 100 parts, CaO and $WO_3$ each 10 to 20 parts, with the CaO, $WO_3$ ratio greater than unity, to keep freezing point low and to prevent the vaporization of $CaCl_2$. The observed decomposition voltage at which $WO_3$ decomposes to W and CO was-0.1 volt, whereas the calculated was -0.3 volt. Metallic tungsten deposited at the cathode reacted easily with CO formed secondarily at the anode surface, to form WC below $1050^{\circ}C$, so that the cell temperature should be above $1050^{\circ}C$. The effects of cathode current densities on current efficiency were minor in the range of 1 to 5 $amp/cm^2$.

• Journal of Periodontal and Implant Science
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• v.50 no.4
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• pp.238-250
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• 2020

Purpose: This study aimed to evaluate the biocompatibility and the mechanical properties of ultraviolet (UV) cross-linked and biphasic calcium phosphate (BCP)-added collagen membranes and to compare the clinical results of ridge preservation to those obtained using chemically cross-linked collagen membranes. Methods: The study comprised an in vitro test and a clinical trial for membrane evaluation. BCP-added collagen membranes with UV cross-linking were prepared. In the in vitro test, scanning electron microscopy, a collagenase assay, and a tensile strength test were performed. The clinical trial involved 14 patients undergoing a ridge preservation procedure. All participants were randomly divided into the test group, which received UV cross-linked membranes (n=7), and the control group, which received chemically cross-linked membranes (n=7). BCP bone substitutes were used for both the test group and the control group. Cone-beam computed tomography (CBCT) scans were performed and alginate impressions were taken 1 week and 3 months after surgery. The casts were scanned via an optical scanner to measure the volumetric changes. The results were analyzed using the nonparametric Mann-Whitney U test. Results: The fastest degradation rate was found in the collagen membranes without the addition of BCP. The highest enzyme resistance and the highest tensile strength were found when the collagen-to-BCP ratio was 1:1. There was no significant difference in dimensional changes in the 3-dimensional modeling or CBCT scans between the test and control groups in the clinical trial (P>0.05). Conclusions: The addition of BCP and UV cross-linking improved the biocompatibility and the mechanical strength of the membranes. Within the limits of the clinical trial, the sites grafted using BCP in combination with UV cross-linked and BCP-added collagen membranes (test group) did not show any statistically significant difference in terms of dimensional change compared with the control group.

• Culinary science and hospitality research
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• v.21 no.4
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• pp.42-54
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• 2015

The purpose of this study was to investigate the quality characteristics of cookies prepared with dropwort powder(0, 2, 4, 6, and 8%) for flour. The bulk density of cookie dough of groups with dropwort powder shows significantly differences when compared to the control group. The pH of cookie dough and cookies were decreased by addition of dropwort powder. The moisture content of the groups with dropwort powder was higher than that of the control group. The weight and width of the groups with dropwort powder was lower than those of the control group. The spread ratio of the groups with dropwort powder was lower but the loss rate of cookies was higher than those of the control group. In color, the L, a, and b value was decreased significantly by addition of dropwort powder. The hardness of the groups with 2% and 4% dropwort powder was higher than that of the control group. DPPH radical scavenging activity of the control group was 20.62%, whereas the groups with dropwort powder ranged from 32.11~65.10%. Sensory evaluation scores in terms of appearance, flavor, taste, texture, and overall preference of groups with 2% and 4% of dropwort powder did not show any significantly differences when compared to the control group. Based on the above results, using less than 4% of the dropwort powder would be proper to make cookies.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.100-112
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• 2014

This study investigates the characteristics of cookies added with yacon. The addition of yacon powder did not affect the density of the cookies and decreased pH level. The moisture content was the highest in the cookies with 12% of yacon. Spread ratio was the highest in the cookies containing yacon powder. The loss rate and leavening rate of the cookies decreased with increasing amounts of yacon powder. Lightness and yellowness decreased significantly while redness increased significantly with a high content of yacon powder in the formulation. The hardness of the control group was higher than that of the cookies prepared with different levels of yacon powder. The antioxidant activity was estimated by DPPH free radical scavenging activity and the total phenolic acid content in yacon powder and cookies. The consumer acceptability score for the 6% yacon cookie group ranked significantly higher than the other groups in overall preference, appearance, flavor, taste and color. Through this experiment, this study exhibited both the functional and health based benefits of yacon when it is added to cookies and confirmed the development feasibility of yacon cookies considering consumer satisfaction.