• Architectural research
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• v.25 no.3
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• pp.53-59
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• 2023

Concrete is widely used in the construction industry; however, it has the disadvantage of deteriorating durability due to cracks occurring because of climate change and shrinkage. In addition, when cement is used as a binder, CO₂ emitted during the manu-facturing process accounts for ~8% of global CO₂ emissions. In this study, ecofriendly cementitious materials such as blast furnace slag powder and fly ash (FA) were used as cement substitutes in the production of mortar containing a chitosan-based polymer (CP), and their fluidity, compressive strength, and self-healing performance were examined. The 28-day compressive strength of the control sample was ~32.4 MPa (the lowest for all tested samples), while that of the sample containing 5% CP and 20% FA was ~49.6 MPa (the highest for all tested samples) and ~53.1% higher than that of the control sample. Even at a healing age of 56 days, the control sample exhibited the lowest healing performance, whereas the samples containing CP (5%, 10%) and 20% FA demonstrated excellent healing performance. After 28 days, the decrease in crack size for the control sample was minimal; however, for the sample containing only cement and CP, a significant decrease in crack size was observed even after 28 days. This study confirmed that the appropriate use of CP and cementitious materials improves not only compressive strength but also the selfhealing performance of mortar.

• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.234-243
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• 2018

In this study, the physicochemical properties of freeze dried (FD) and spray dried powders (SD-MD10, SD-MD20, SD-CD10, SD-CD20) from green coffee bean extract were investigated. Yields were 91.46% for FD powder and 71.63~87.98% for SD powders, respectively. The moisture content of SD powders (1.39~1.86%) was lower than that of FD powder (3.19%). L, a and b value of SD powders were higher than of FD powder. The particle size of the FD powder ($147.67{\mu}m$) was higher than that of the SD powders ($54.23{\sim}66.07{\mu}m$). The water absorption index of the SD powders (0.51-0.59) were lower than that of the FD powder (0.72). The water solubility index of the SD powders, 77.26-90.07%, was higher than that of the FD powder (70.07%). The total phenolic and flavonoid contents of SD-CD10 were 20.67 g/100 g and 8.92 g/100 g, respectively. The chlorogenic acid content of SD-CD10 (12.04 g/100 g) was higher than other SD powders. The DPPH and superoxide radical scavenging activities of SD-CD10 at $1,000{\mu}g/mL$ were 88.02% and 86.89%, respectively. The SD-CD10 was better than other SD powders on protective effects against oxidative stress in L-132 cells (87.33%). In conclusion, we provided experimental evidence that spray-dried powder of green coffee bean extracts have potential as functional food materials.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.121-134
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• 2011

For this study, Smilex powder, a pesticide, was sprayed on the Altari radish, and then underground water, Chitosan solution (${\times}$500), and wood vinegar solution (${\times}$1000) were evenly sprayed on the Altari radish respectively. Samples of Altari radishs for residual pesticide analysis were taken two hours, 1 day, 7 days, and 15 days after treatments, and the detectable concentration and degradability of procymidone, the pesticide residue, were measured. The results obtained are as follows: 1. When detectable concentration of procymidone within the altari radish was measured, treatment plots sprayed with underground water, Chitosan solution (${\times}$500), and wood vinegar solution (${\times}$1000) were found to show lower detectable concentration than the non-treatment plot which was sprayed with pesticide only. Especially, the treatment plots sprayed with Chitosan solution (${\times}$500), and with wood vinegar solution (${\times}$1,000) showed lower values than the average. 2. When the degradability of procymidone within the Altari radish was measured, the plot treated with Chitosan solution (${\times}$500) and the plot treated with wood vinegar solution (${\times}$1,000) were found to have relatively higher degradability of procymidone. There were not much differences among testing materials in the degradability of residual pesticides. However, the plot treated with Chitosan solution (${\times}$500) showed higher degradability. In terms of average degradability with time, degradability increased sharply 7 days after the foliar application of testing materials. 3. When the daily far-sighted view survey was conducted in order to find out growth disorder and damage on the Altari radish plants by the treatment of un-derground water, Chitosan solution (${\times}$500), and wood vinegar solution (${\times}$1,000), no symptomatic physiological disorders was observed on all the plants tested during the whole growing season at the tested concentration level.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1011-1019
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• 1998

The natural dyestuff(squid ink) was manufactured from squid ink by boiling in 0.1% NaOH solution and powdering in freeze dryer. Cotton, wool, silk and nylon fabrics were dyed under several conditions using the manufactured squid ink to investigate the dyeability and color fastness. Dyeing was operated in acidic dyebath of pH 4 because the squid ink is anionic. Dyeabilities on wool, silk and nylon fabrics were good, especially silk fabrics were dyed deeper than others because of being amine group. But dyeability on cotton fabrics was low and developed with chitosan treatment. All the dyed fabrics showed excellent in color fastness to crocking and laundering. Also light fastness of them were excellent except nylon. The light fastness of dyed-nylon fabrics was as poor as grade 1, but they could be improved to grade 4 by aftertreatment with gallicacid. Useing the natural dyestuff-squid ink powder, we could execute whenever we want to dye fabrics in the adequate concentration. Dyeabilities were developed according to repeating times of dyeing and the increased dye concentration. We could recycle the wasting sources.

• Textile Coloration and Finishing
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• v.13 no.1
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• pp.23-31
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• 2001

To improve the dyeability and colorfastness of cotton and silk fabric dyed with natural dye of safflower, cotton and silk fabrics were pre-treated with different mordants such as halliic-acid, alum, brine and tannic-acid. Also, to investigate the effect of finishing treatment of fabrics on dyeability, cotton was treated with chitosan and mercerized before dyeing. L, a, b, ΔE and colorfastness(light, Laundry, sweat) of each samples were measured and compared. Mordant treatment didn't improved significantly dyeability and colorfastness on cotton and silk. But, on cotton mercerization and chitosan treatment improved dyeability and colorfastness. To compare the efficiency of extracted dye and Powered dye, extracted red dye of safflower prepared as powder. Cotton and silk were dyed with dyeing solution which made with powdered dye according to different concentration. Efficiency of powdered dye was found out lower than extracted dye solution.

• Korean Journal of Veterinary Research
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• v.58 no.3
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• pp.119-124
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• 2018

This study was conducted to compare the hemostatic efficacy of three ferric subsulfate- and chitosan-based styptics as a powder and a gel containing ferric subsulfate and chitosan (FSC-PO and FSC-G, respectively) and a soaked pad containing ferric subsulfate and lidocaine (FSL-SP) using a rat tail bleeding model. The cytotoxicity of the styptics against L-929 mouse fibroblasts was also evaluated using a cell counting kit-8 assay. Four groups of 10 rats each were assigned to the three different styptics and a non-treated control groups. Rat tail tips were transected, after which styptics were applied with pressure. The wounds were observed for hemostasis for 3 min, then irrigated with saline to check for recurrent hemorrhage. L-929 mouse fibroblasts were exposed to extracts of the styptics (100 mg/mL) and their dilutions (1:10, 1:100, and 1:1,000). FSC-PO and FSC-G more effectively controlled initial hemorrhage than FSL-SP (p = 0.033). Additionally, FSC-PO and FSC-G more effectively maintained hemostasis than the control group (p = 0.02 and p < 0.01, respectively). However, all styptics showed enhanced cytotoxicity against L-929 cells in a dose-dependent manner. Therefore, although FSC-PO and FSC-G would be recommended to control hemorrhage, the benefits of styptics must be balanced against the clinical significance of their cytotoxicity.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.1-23
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• 2001

Chitosan is biodegradable natural polymer that has been demonstrated its ability to improve wound healing, and calcium metaphosphate(CMP) is a unique class of phosphate minerals having a polymeric structure. In this study, chitosan/CMP and platelet derived growth factor(PDGF-BB) loaded chitosan/CMP sponges were developed, and the effect of the sponges on bone regeneration and their possibility as scaffolds for bone formation by three-dimensional osteoblast culture were examined. PDGF-BB loaded chitosan/CMP sponges were prepared by freeze-drying of a mixture of chitosan solution and CMP powder, and soaking in a PDGF-BB solution. Fabricated sponge retained its 3-dimensional porous structure with $100-200\;{\mu}m$ pores. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with $^{125}I-labeled$ PDGF-BB. In order to examine their possibility as scaffolds for bone formation, fetal rat calvarial osteoblastic cells were isolated, cultured, and seeded into the sponges. The cell-sponge constructs were cultured for 28 days. Cell proliferation, alkaline phosphatase activity were measured at 1, 7, 14 and 28 days, and histologic examination was performed. In order to examine the effect on the healing of bone defect, the sponges were implanted into rat calvarial defects. Rats were sacrificed 2 and 4 weeks after implantation and histologic and histomorphometrical examination were performed. An effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. PDGF-BB loaded chitosan/CMP sponges supported the proliferation of seeded osteoblastic cells as well as their differentiation as indicated by high alkaline phosphatase activities. Histologic findings indicated that seeded osteoblastic cells well attached to sponge matrices and proliferated in a multi-layer fashion. In the experiments of implantation in rat calvarial defects, histologic and histomorphometric examination revealed that chitosan/CMP sponge promoted osseous healing as compared to controls. PDGF-BB loaded chitosan/CMP sponge further echanced bone regeneration. These results suggested that PDGF-BB loaded chitosan/CMP sponge was a feasable scaffolding material to grow osteoblast in a three-dimentional structure for transplantation into a site for bone regeneration.

• Journal of the Korean Ceramic Society
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• v.50 no.4
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• pp.245-250
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• 2013

A hydroxyapatite air filter was made with hydroxyapatite powder, water and chitosan solution. The structures of the sintered HAp samples were determined by MP-XRD. Hydroxyapatite has antibacteria properties against Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. The bacteria removal rate was 99.9%. In the case of Pseudomonas aeruginosa, Colon bacterium and Listeria monocytogenes, the hydroxyapatite air filters had a clear zone which confirmed antibacteria properties. Using the microscopy, we observed that the HAp powder absorbed E. coli bacteria.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.779-784
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• 2006

To produce bio-active Kochujang, 1.2% of pomegranate powder, 1.0% of hawthorn berry extract powder, 0.01% of ginko biloba extract, 1.2% of red yeast rice powder, 1.2% of silk powder, 0.2% of garlic oil, 0.2% of chitosan, 1.2% of wax gourd extract powder, and 1.0% of pine mushroom were added individually with raw materials that are needed for Kochujang process. These Kochujangs were fermented for 45 days at $30^{\circ}C$, and examined for changes in their physicochemical properties. There were no significant differences in pH, acidity, formol-N content, color and total cell count by plate count agar between Kochujangs fortified individually with functional ingredients and the control Kochujang. When 0.2% of garlic oil was added, antioxidant activity of its Kochujang product increased twice as much as that of the control Kochujang. Improved ACE inhibiting activities were observed in 1.2% of red yeast rice powder. When 1.2% of silk powder or 0.01% of ginko biloba extract were added, antithrombotic abilities were remarkably enhanced up to two times of the control Kochujang.

• Korean Journal of Poultry Science
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• v.26 no.3
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• pp.203-211
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• 1999

This study was performed to develop brand egg. Forty-four week-old Isa Brown were randomly assigned to 8 treatments and the number of hens were 300 per each group. Experimental period was about 10 weeks. The 8 treatment were as follows : astarich 2%(A), astarich 5%(B), chitch chitosan 2%(C), omega-3 powder 2%(D), pyrogreen 1%(E), greenpia 0.2%(F), hydrogenated soy oil 3%(G) and commercial layer feed(H). Eggs were collected at day 0, 7, 14, 40 and 70 for egg quality analyses. Laying rate was significantly higher in astarich groups(B, C) than ant other group, showing average of 88% of laying rate. In terms of egg factors, whole egg weight was the heaviest in control in control(A) and the lightest in omega-3 powder group(E), while egg yolk weight was the heaviest in astarich group(H). Haugh unit(HU) was the mean of 70 for all treatments and there were no significant differences among the treatments. Egg yolk color was significantly different among treatments during experimental period whenever yolk color was measured. At the day 7 after feeding of experimental diets, the yolk color of astarich 5% group(C) was darker and that of omega-3 powder group(E) lighter. The value of yolk color in astarich 5%(C) and 2%(B) was 14.2 and 12.5, respectively. But the rest of the groups did not show any differences in yolk color, showing mean of 11.5. In terms of shell thickness, shell tended to become thinner, but there were no defferences among treatments during experimental period. The mean value of shell thickness was 0.390mm. In conclusion, astarich groups may seem to produce the best possible quality of brand egg.