• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.611-618
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• 2008

CFRP (carbon fiber reinforced polymer) tendons can be used as an alternative to solve the corrosion problem of steel tendons. Since CFRP tendons are vulnerable to transverse pressure and stress concentration, the conventional anchorage system used for steel tendons can create an unreliable load carrying capacity and may result in a premature failure. Therefore, it is necessary to develop the anchorage system that is well suited for CFRP tendons. There are many types of anchorage systems for CFRP tendons, which can be classified into three types: wedge-type anchorage, bond-type anchorage, and compression-type anchorage. This paper deals with the compression-type anchorage system manufactured through swaging technology. Based on the previous test results performed by the authors, the dimension of anchorage sleeve, the use and non-use of the insert, and the compression pressure on the sleeve have been selected as the major parameters affecting the performance of the compression-type anchorage. Some anchorage sleeves have been tapered to reduce the stress concentration. Test results revealed that the performance of the anchorage system depends mainly on the dimension and the compression pressure. It has been verified that the tapered sleeve can effectively reduce the stress concentration.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.229-240
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• 1972

Not only in order to determine reasonable application amounts of PCP in terms of soil texture, but also to get basic data for fish-toxicity-free treatment by estimating fish toxicity, some aspects of PCP adsorption were observed taking various paddy soils with different physico-chemical characteristics in the Choongbook Area as samples. The results obtained are summarized as follows: 1. There was a positive correlation between PCP adsorption and clay contents, total nitrogen, organic matter, cation exchange capacity, exchangeable bases, and phosphorus absorption coefficients, respectively; whereas there was a negative one between PCP adsorption and pH. Although they were not significant, it was remarkable that there was a relatively large amount of correlation between PCP adsorption and clay contents, $H^+,\;Mg^{++}$, and CEC, respectively. 2. PCP adsorption in terms of soil texture was in the order of Clay>Loam>Sandy loam. 3. Although PCP adsorption in the $H_2O_2-treated$ soils decreased remarkably, it was not proportional to the humus contents. 4. The order of PCP adsorption in the exchangeable base-treated soils was H^+-exchanged soil>$K^+-soil$>$Na^+-soil$>$Ca^{++}-soil$>Mg^{++}-soil. 5. Langmuir's and Freundlich's adsorption isotherms were applicable to the PCP adsorption, and thereby were able to be calculated maximum adsortion amounts of PCP, bond energy, and the depths of adsorption layers. 6. Maximum adsorbed amounts of PCP were 212.14 mg/100gr in Clayey loam, 97.28 to 121.59mg/100gr in Loam, and 32.92 to 91.74mg/100gr in Sandy loam, respectively. 7. The depths of mixed layers of limiting application for fish-toxicity-free treatment were 0.88cm of the Jinchun soil, the shallowest and 4.29 cm of the Naesan-ri Sandy loam, the deepest.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.13-22
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• 2007

This study was carried out to scrutinize possibility of manufacturing pitch pine (Pinus rigida) glued laminated timber in order to add values of pitch pine trees. Also, it was investigated to improve bending performance of pitch pine glulam. Pitch pine was imported as one of major plantation species in Korean peninsula. Machine stress rated grades of pitch pine lumber mostly ranged between E7 and E9. which grades were more or less inferior to producing high quality glulam. However, the adhesive properties between pitch pine and pitch pine, and between pitch pine and Japanese larch (Larix kaempferi Carr.), such as shear bond strength, wood failure rate and de-lamination rate of bonded layer submerged in cold and boiling water, were higher than Korean Standard criteria. These properties are essential for manufacturing glulam with single species or multiple species. The modulus of rupture (MOR) of pitch pine glulam exceeded the criterion of Korean Standard for glulam strength grade but modulus of elasticity (MOE) was lower than the criterion. On the other hand, the bending performances (MOR and MOE) were improved 20 percent by mixing with Japanese larch laminar. It is effective to arrange higher quality Japanese larch laminar at the outer layer of glulam for improving bending performances. In conclusion, it is possible to use low quality pitch pine as laminar of structural glulam for adding values of pitch pine.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.50-60
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• 2008

The majority of the described experimental results deal with relatively pure aluminium. Variations were made in the pretreatment of the aluminum substrates and an investigation was performed on the resulting changes in oxide layer composition and chemistry. Subsequently, the bonding behavior of the surfaces was investigated by using model adhesion molecules. These molecules were chosen to represent the bonding functionality of an organic polymer. They were applied onto the pretreated surfaces as a monolayer and the bonding behavior was studied using infrared reflection absorption spectroscopy. A direct and clear relation was found between the hydroxyl fraction on the oxide surfaces and the amount of molecules that subsequently bonded to the surface. Moreover, it was found that most bonds between the oxide surface and organic functional groups are not stable in the presence of water. The best performance was obtained using molecules, which are capable of chemisorption with the oxide surface. Finally, it was found that freshly prepared relatively pure aluminum substrates, which are left in air, rapidly lose their bonding capacity towards organic functional groups. This can be attributed to the adsorption of contamination and water to the oxide surface. In addition the adhesion of a typical epoxy-coated aluminum system was investigated during exposure to water at different temperatures. The coating was found to quite rapidly lose its adhesion upon exposure to water. This rapid loss of adhesion corresponds well with the data where it was demonstrated that the studied epoxy coating only bonds through physisorptive hydrogen bonding, these bonds not being stable in the presence of water. After the initial loss the adhesion of the coating was however found to recover again and even exceeded the adhesion prior to exposure. The improvement could be ascribed to the growth of a thin oxyhydroxide layer on the aluminum substrate, which forms a new, water-stable and stronger bond with the epoxy coating. Two routes for improvement of adhesion are finally decribed including an interphasial polymeric thin layer and a treatment in boiling water of the substrate before coating takes place. The adhesion properties were finely also studied as a function of the Mg content of the alloys. It was shown that an enrichment of Mg in the oxide could take place when Mg containing alloys are heat-treated. It is expected that for these alloys the (hydr)oxide fraction also depends on the pre-treatment and on the distribution of magnesium as compared to the aluminium hydroxides, with a direct impact on adhesive properties.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.1 s.47
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• pp.41-49
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• 2006

Through the 1982 Urahawa-ohi and the 1995 Kobe earthquakes, a number of bridge columns were observed to develop a flexural-shear failure due to the bond slip as a consequence of premature termination of the column longitudinal reinforcement. Because the seismic behavior of RC bridge piers is largely dependent on the performance of the plastic hinge legion of RC bridge piers, it is desirable that the seismic capacity of RC bridge pier is to evaluate as a curvature ductility. The provision for the lap splice of longitudinal steel was not specified in KHBDS(Korea Highway Bridge Design Specification) before the implementation of 1992 seismic design code, but the lap splice of not more than 50%, longitudinal reinforcement was newly allowed in the 2005 version of the KHBDS. The objective of this research is to investigate the distribution and ductility of the curvature of RC bridge column with the lap splice of longitudinal reinforcement in the plastic hinge legion. Six (6) specimens were made in 600 mm diameter with an aspect ratio of 2.5 or 3.5. These piers were cyclically subjected to the quasi-static loads with the uniform axial load of $P=0.1f_{ck}A_g$. According to the slip failure of longitudinal steels of the lap spliced specimen by cyclic loads, the curvatures of the lower and upper parts of the lap spliced region were bigger and smaller than the corresponding paris of the specimen without a lap splice, respectively. Therefore, the damage of the lap spliced test column was concentrated almost on the lower part of the lap spliced region, that appeared io be failed in flexure.

• Tunnel and Underground Space
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• v.26 no.3
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• pp.220-234
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• 2016

Sprayable waterproofing membrane has been considered as a substitute for a sheet waterproofing membrane in a variety of underground excavation works. However, fundamental properties of sprayble waterproofing membrane have not been fully given yet. In this study, a new two-component sprayable waterproofing membrane prototype was developed. In addition, its physico-mechanical properties were measured and compared with those of two kinds of thin spray-on liners where constitutive materials and construction methods are very close to each other. From direct tensile tests, the sprayable waterproofing membrane with elongations at break between 250% and 300% showed much higher ductility than TSLs. However, the sprayable waterproofing membrane had a limitation as a support member since its bond strength and loading capacity was lower than those of TSLs. From three-dimensional X-ray CT images, the porosity of the sprayable waterproofing membrane was estimated to be 26.13%. However, most of pores which might have been generated during membrane curing were not observed to be interconnected but isolated.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.184-192
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• 2022

Porous NiO synthesized via hydrothermal synthesis was used in the electrodes of lithium-sulfur batteries to inhibit the elution of lithium polysulfide. The electrode of the lithium-sulfur battery was manufactured as a freestanding flexible electrode using an economical and simple vacuum filtration method without a current collector and a binder. The porous NiO-added S/CNT/NiO electrode exhibited a high initial discharge capacity of 877 mA h g^-1 (0.2 C), which was 125 mA h g^-1 higher than that of S/CNT, and also showed excellent retention of 84% (S/CNT: 66%). This is the result of suppressing the dissolution of lithium polysulfide into the electrolyte by the strong chemical bond between NiO and lithium polysulfide during the charging and discharging process. In addition, for the flexibility test of the S/CNT/NiO electrode, the 1.6 × 4 cm² pouch cell was prepared and exhibited stable cycle characteristics of 620 mA h g^-1 in both the unfolded and folded state.

• Sim-seong Yeon-gu
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• v.31 no.2
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• pp.177-214
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• 2016

This thesis is an interpretation of "Golden bird" of Grimm's fairy tale and similar other tales from the perspective of analytical psychology. Golden bird story start loss of golden apple in king's garden. King and three sons are one-sided structure live without female members in family. They need feminine aspect. Adventure and journey of stupid youngest son can be seen as a individuation process in analytic psychology. Ego meets several painful experience during journey. New Kingdom has a new specific collective consciousness. When ego fixed dominated specific collective consciousness he can only be liberated after completing the difficult task of the next phase in crisis of death. This process is initiation, which is a supplement to feminity after recovery of increased consciousness, marriage with the princess, which is possible to unify the sexes (coniunctio oppositorum). The ego who got the apple, bird, horse, and princess which is shown to be a supplement to feminity, does not attain a complete success. Although the youngest comes out after brothers' failure, yet separation and abandonment of persona are difficult challenges and after all he achives a higher consciousness and then he primarily marries the princess, his Anima, after he executed his brothers for his repeated hardships, when the intellectual capacity is sacrificed as offering. Also, the fox restores himself from magic after the youngest son kills him and cut his head and feet, as the fox's wish. To be transformed into a human being. It experiences another consciousness. Finally, unifying the coniunctio oppositerum is fulfilled and a divine bond achieves the wholeness and it is accomplished individuation. In clinical practice, fox is compared to a therapist as a guide of individuation process who lead clients.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.711-722
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• 2011

Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.