• Journal of the Korean Wood Science and Technology
• /
• v.23 no.4
• /
• pp.33-38
• /
• 1995

The rates of fixation of CCA-Type B and CCFZ in blocks of radiata pine sapwood were compared at various temperatures and conditioning methods (drying and nondrying conditioning). Also the time required to proper fixation of preservative components in the treated wood was estimated. Fixation was monitored by the rates of depletion of free hexavalent chromium in the cell lumens in the teated blocks. The rate of preservative fixation in wood was highly temperature dependent. The fixation rate was considerably accelerated by means of heating and complete fixation of hexavalent chromium was achieved within about 12 hours by heating at $60^{\circ}C$. The moisture content of treated wood during fixation apparently played an important role in the fixation process. The fixation rate of treated wood conditioned in nondrying conditions was much more faster than that of treated wood conditioned in drying conditions. particularly when the moisture content of treated wood was below fiber saturation point. Time required to full fixation could be predicted successfully using the fixation temperatures applied since the correlation between the fixation temperature and the fixation time was excellent. regardless of conditioning methods.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.165-166
• /
• 2017

Corrosion of reinforcement is the main factors affecting the durability of reinforced concrete in the world which lead to the failure of structures of reinforced concrete buildings. In this research, mixed brucite(Mg(OH)₂) into ordinary portland cement paste in ratio of 5, 10 and 15% as a kind of CO₂ fixation material. Samples were exposed to an accelerated carbonation enslavement of 20% CO₂ concentration, 60% relative humidity, and a temperature of 20℃ until tested at 3d, 7d, 14d and 28d. After 28d CO₂ accelerated curing, in the paste containing MH megnesian calcite was found by XRD and SEM-EDX. Meanwhile, paste containing Mg(OH)₂ exhibit the better pore distribution than ordinary portland cement paste and relatively good compressive strength.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.44-49
• /
• 2003

This study was carried out to evaluate the weathering durability of waterborne preservative (AAC, ACQ, CCA, CuAz) treated Japanese red pine (Pinus densiflora S. et Z.) sapwood samples by accelerated weathering, and to find out the factor of stability. When considered the color changes, weight losses, surface degradation, and microstructure changes due to weathering, ACQ-, CCA-, and CuAz-treated samples were durable against weathering; the weathering durability of AAC-treated samples was poor and similar to untreated controls. The lignin content in aqueous extracts collected from ACQ-, CCA-, and CuAz-treated samples during weathering was lower than that from untreated and AAC-treated ones. From these findings, we might concluded that weathering durability of ACQ-, CCA-, and CuAz-treated samples was enhanced by the fixation of preservative component(s) onto the lignin structure, which is very susceptible to weathering.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.38-43
• /
• 2003

This is the second in a series of reports on the evaluation of weathering durability of waterborne preservative treated wood by accelerated weathering. The leaching of copper from ACQ-, CCA-, and CuAz-treated samples during weathering was increased by UV irradiation, when compared between full weathering and water-only weathering. The FTIR spectra of the weathered ACQ-, CCA, CuAz-treated samples at 1731 cm^-1, 1625 cm^-1, 1510 cm^-1, which are related to the fixation of copper, were different from those of unweathered controls. This result means that UV irradiation can weaken the chemical bond between lignin and copper and/or extraction of lignin-copper complex can be occured when lignin erode away by weathering.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.21 no.1
• /
• pp.81-88
• /
• 1999

A fibrin adhesive have been widely used in oral and maxillofacial surgery for microvascular anastomosis, autogenous chip bone grafts, many kinds of soft tissue surgery (vestibuloplasty, bleeding control after extraction, primary healing by covering of suture of a gum after the extirpation of large cysts). There are two principal components in adhesive systems biologically: lyophilized human fibrinogen and bovine thrombin. The fibrinogen component contains coagulation factor XIII and enhance the initial wound healing, which polymerizes soluble fibrin monomers into an insoluble clot. The thrombin is dissolved in a solution of calcium chloride to provide the second component. We applied fibrin adhesive, Beriplast (Behring, Behringwerke AG, D-3350, Marburg, FRD), to 4 patients for fixation of free skin grafting donors who had facial scar around eye, nose, mouth corner which received from accidents, or burn. We have experienced initial accelerated graft fixation between donor and recipient sites with no additional fixation. And It's made easy bleeding control and easy manipulation during operation. But two cases showed partial hypertrophic scar engrowth in above 3 months follow up, but no significant. Histopathological reviews in general were showed similar scar findings such as abundant collagen bundles in H&E, M/T stain, but slight positive signs in elastic and collagen antibody immunopathologic findings in hypertrophic scar cases.

• Journal of Korean Foot and Ankle Society
• /
• v.17 no.2
• /
• pp.106-114
• /
• 2013

Purpose: Posteroanterior screw fixation is biomechanically stronger than anteroposterior screw fixation. However, there are few literature about the correlation between clinical results and more strength by posteroanterior fixation. This study was performed to evaluate the clinical outcomes of the accelerated rehabilitation following anterior open reduction and posterior percutaneous screw fixation for displaced talar neck fractures. Materials and Methods: Eighteen cases were followed up for more than 1 year after posteroanterior fixation using headless compression screw for talar neck fractures. The clinical evaluation was performed according to American Orthopaedic Foot and Ankle Society (AOFAS) score and Hawkins criteria. As radiographic evaluation, the degree of fracture displacement, period to union, and occurrence rate of complications such as avascular necrosis through MRI were measured. Results: The AOFAS score was average 90.4 points at the last follow-up. There were 7 excellent, 9 good, and 2 fair results according to the Hawkins criteria. Therefore, 16 cases(88.8%) achieved satisfactory results. The degree of fracture displacement had improved significantly from preoperative average 5.6 mm to 1.2 mm immediate postoperatively, and maintained to 1.1mm at the last follow-up. All cases achieved bone union, and the period to union was average 12.4 weeks. There were 3 cases of avascular necrosis of talar body and 2 cases of post-traumatic arthritis. Conclusion: Anterior open reduction and posterior percutaneous headless screw fixation seems to be an effective surgical method for displaced talar neck fractures, because of the possibility of accurate restoration of articular surface, fixation strength enough to early rehabilitation, and needlessness of hardware removal.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.3
• /
• pp.203-210
• /
• 2018

Corrosion of the rebar is one of the main factors affecting the durability of reinforced concrete in the world which lead to the failure of the reinforced concrete structures. In this research, a new method of fixing $CO_2$ is practiced to improve the carbonation resistance of the concrete. Brucite($Mg(OH)_2$), a kind of common $CO_2$ fixation materials, was added into ordinary Portland cement paste. Samples containing 0%, 5%, 10%, and 15% $Mg(OH)_2$ were exposed to an accelerated carbonation curing regime with 20% concentration of $CO_2$, 60% relative humidity, and a temperature of $20^{\circ}C$ until tested at 3d, 7d, 14d and 28d. After 28d of $CO_2$ accelerated curing, in the paste containing $Mg(OH)_2$, magnesian calcite was detected by SEM-EDX. Meanwhile, the paste containing $Mg(OH)_2$ exhibit the better pore distribution than ordinary Portland cement paste and the compressive strength of the cement paste containing $Mg(OH)_2$ were more than 50Mpa.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.24-25
• /
• 2017

Gamma-C₂S (γ-C₂S) is a substance that is difficult to react with water under normal temperature but can absorb a large amount of CO₂ in the air. The addition of γ-C₂S to cementitious materials through the curing of CO₂ can improve the pore structure and improve the durability of the material. In this study, three kind of Ca-bearing materials : CaO, Ca(OH)₂, CaCO₃, were calcined 2.5h at 1450℃ to synthesize γ-C₂S after mixing with SiO₂ respectively. Among them, Ca(OH)₂ mixed with SiO₂ after calcining shows highest content. Synthesized γ-C₂S was added to the cement mortar, after water curing for 1 month, accelerated carbonation test was experimented. After 28d accelerated carbonation test, pore structure will be detectived by MIP. Based on the MIP result, following the calculation method of Fractal theory, the pore structure will be quantitative described.

• Journal of the Korean Arthroscopy Society
• /
• v.14 no.1
• /
• pp.33-35
• /
• 2010

This is a case of the core reamer breakage during anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft. A 19-year-old man with acute anterior cruciate ligament rupture had reconstruction surgery. During tunneling in the proximal tibia, the core reamer have been cracked open and broken. Rest of the procedure was performed routinely except the tibial sided fixation of bone block which was performed with larger interference screw than usual. The patient followed the accelerated rehabilitation program. The result was satisfactory at 2 years after surgery.

• Journal of Ginseng Research
• /
• v.46 no.1
• /
• pp.1-10
• /
• 2022

Ginseng has been well-known as a medicinal plant for thousands of years. Bacterial endophytes ubiquitously colonize the inside tissues of ginseng without any disease symptoms. The identification of bacterial endophytes is conducted through either the internal transcribed spacer region combined with ribosomal sequences or metagenomics. Bacterial endophyte communities differ in their diversity and composition profile, depending on the geographical location, cultivation condition, and tissue, age, and species of ginseng. Bacterial endophytes have a significant effect on the growth of ginseng through indole-3-acetic acid (IAA) and siderophore production, phosphate solubilization, and nitrogen fixation. Moreover, bacterial endophytes can protect ginseng by acting as biocontrol agents. Interestingly, bacterial endophytes isolated from Panax species have the potential to produce ginsenosides and bioactive metabolites, which can be used in the production of food and medicine. The ability of bacterial endophytes to transform major ginsenosides into minor ginsenosides using β-glucosidase is gaining increasing attention as a promising biotechnology. Recently, metabolic engineering has accelerated the possibilities for potential applications of bacterial endophytes in producing beneficial secondary metabolites.