• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.38-45
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• 2005

The feasibility of stimulating in situ aerobic cometabolic activity of indigenous microorganisms was investigated in a trichloroethylene (TCE)-contaminated aquifer. A series of single-well natural drift tests (SWNDTs) was conducted by injecting site groundwater amended with a bromide tracer and combinations of toluene, oxygen, nitrate, ethylene and TCE into an existing monitoring well and by sampling the same well over time. Three field tests, Push-pull Transport Test, Drift Biostimulation Test, and Drift Surrogate Activity Test, were performed in sequence. Initial rate of toluene degradation was much faster than the rate of bromide dilution resulting from natural groundwater drift, indicating stimulation of indigenous toluene-oxidizing microorganisms. Transformation of ethylene, a surrogate probing overall activity of TCE transformation, was also observed, and its transformation results in the production of ethylene oxide, suggesting that some tolueneoxidizing microorganisms stimulated may express a orthomonooxygenase enzyme. Also in situ transformation of TCE was confirmed by greater retardation of TCE than bromide after the stimulation of toluene-oxidizing microorganisms. These results indicate that, in this environment, toluene and oxygen additions stimulated the growth and aerobic cometabolic activity of indigenous microorganisms expressing orthomonooxygenase enzymes. The simple, low-cost field test method presented in this study provides an effective method for conducting rapid field assessments and pilot testing of aerobic cometabolism, which has previously hindered application of this technology to groundwater remediation.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.75-82
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• 2011

Five different composition UV-cured poly(urethane acrylate-co-acrylic acid) (PU-co-AA) films have been prepared by reacting isophorone diisocyanate(IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), and different weight ratio trimethylolpropane triacrylate(TMPTA) and acrylic acid(AA) as diluents, and characterized using a Fourier transform infrared spectroscopy(FT-IR). The adhesion properties onto the stainless steel, morphology, mechanical hardness, and electrical property of UV-cured PU-co-AA films were investigated as a function of acrylic acid(AA) content. All the PU-co-AA films are structure-less and the molecular ordering and packing density decreased with increasing content of AA due to the flexible structure and -COOH side chains in AA. The crosscut test showed that PU-co-AA films without AA and with low content of AA showed 0% adhesion(0B) and the adhesion of PU-co-AA films in the range of 40-50% AA increased dramatically as the content of AA increases. The pull-off measurements showed that the adhesion force of PU-co-AA films to stainless steel substrate varied from 6 to 31 kgf /$cm^2$ and increased linearly with increasing AA content. The mechanical hardness also decreased as the content of AA increases. This may come from relatively linear and flexible structure in AA and low crystallinity in PU-co-AA films with higher content of AA. The higher AA-containing PU-co-AA films showed higher dielectric constant due to the increase of polarization by introducing AA monomer. In conclusion, the physical properties of UV-cured PU-co-AA films are strongly dependent upon the content of AA and the incorporation of AA in polyurethane acrylate is very useful way to increase the adhesion strength of UV-curable polymers on the stainless steel substrate.

• Elastomers and Composites
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• v.35 no.1
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• pp.53-62
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• 2000

Zinc plated steel tire cords were treated with RF plasma polymerization coating of acetylene or butadiene in order to enhance adhesion to rubber compounds. Plasma polymerization was carried out as a function of plasma power, treatment tune and gas pressure. In order to maximize adhesion, argon plasma etching was performed, with carrier gas such as argon, nitrogen and oxygen, while the adhesion of tire cords was evaluated via TCAT. Best results were obtained from a combination treatment of argon etching (90 W. 10 min, 30 mTorr) and acetylene plasma polymerization coating (10 W, 30 sec, 30 mTorr) with argon carrier gas (25/5:acetylene/argon). These samples exhibited a pull out force of 285N which is comparable to that obtained from the brass plated tire cords (290N).

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.487-496
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• 2014

In this study, three kinds of polymers based on phenothiazine-benzothiadiazole were synthesized by a Suzuki coupling reaction, and the various side-chains were substituted at the nitrogen of phenothiazine. The optical and electrochemical properties of synthesized polymers were analyzed. The results indicate that their absorption ranged from 300 to 700 nm, and also confirmed the ideal highest occupied molecular orbital (HOMO) energy level was about -5.4 eV with low band-gap energy. Photovoltaic devices were fabricated using a photoactive layer composed of a blended solution of the polymer and $PC_{71}BM$ in ortho-dichlorobenzene The device with P2HDPZ-bTP-OBT containing the branched side-chain and long chain showed the best performance; the maximum power conversion efficiency of this device was 2.4% (with $V_{OC}$ : 0.74 V, $J_{SC}$ : $6.9mA/cm^2$, FF : 48.0%).

• Journal of the Korean Geotechnical Society
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• v.30 no.1
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• pp.5-16
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• 2014

This paper presents the results of an investigation into the pullout characteristics of screw anchor pile using field pullout tests. A series of field pullout tests were performed on screw anchor piles with different geometric characteristics such as shaft and screw diameters. The results indicated that screw anchor piles exhibited significantly higher pullout capacities compared with the same diameter piles without screw. Also observed is that the set-up effect and the grouting significantly increase pullout capacities, although the magnitude of the increase depends on the ground condition. In addition the applicability of prediction methods for helical pile pullout capacity to screw anchor piles was also examined. The results are presented in such a way that the pullout characteristics of screw anchor piles with different installation conditions can be identified. Practical implications of the findings are discussed.

• Korean Journal of Cleft Lip And Palate
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• v.15 no.1
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• pp.21-28
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• 2012

Unilateral cleft lip is not a simple and independent problem in all aspects. nasal deformity results from the cleft lip, maxillary hypoplasia, and abnormal muscular pull on the nasal structures, including abnormal muscular tension on the alar base and abnormal position of the orbicularis oris muscle. Its gross and histopathologic characteristics include widening of the alar base, a midline deviation of the columella and septum to the noncleft side, dorsal displacement of the dome, lateral rotation of medial crura, buckling of the alar cartilage, and underdevelopment of the pyriform aperture. Since Dr. Millard first presented his method for repair of the unilateral cleft lip and nasal deformity in 1955, no other technique has gained as much popularity as the rotation-advancement principle. Principles established more than 50 years ago and techniques are evolving continuously. Unlike earlier procedures, this repair gives the surgeon the opportunity to manipulate the individual cleft elements through various modifications while maintaining Millard's original surgical and anatomical goals. Although this strategy is applied worldwide, successful execution is variable and highly operator dependent. Millard and many other surgeons have made technical variations to adjust the procedure to each specific patient, to address some of its faults, and to gain new advantages. We will review the Mulliken's modifications that Dr. Millard made to his original rotation-advancement principle and inform cases applied modifying the rotation-advancement principle.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.108-114
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• 2018

Degradations of durability and aesthetic performance in concrete happen during service life due to surface deterioration and dirt stains. Recently, many researches have been performed on self-cleaning and surface enhancement through surface impregnant using photocatalytic reaction with VOCs(Volatile Organic Compounds) removal. This paper is for preliminary study on surface impregnation with silicate and photocatalysis - $TiO_2$. For the work, two types of silicate based impregnants(CS - Coloidal Silica and SC - Sodium Alumina Silicate) are considered. Several tests for viscosity and surface tension are performed, and pull-off test on impregnated concrete is performed. For the surface impregnated concrete, $TiO_2$ is absorbed through submerging and spraying conditions. Through compressive strength test and SEM analysis, it is evaluated that spraying $TiO_2$ on surface impregnated concrete after 30min. of drying period is very effective both for strength enhancement and surface densification.

• Journal of the Korean Geotechnical Society
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• v.33 no.1
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• pp.39-56
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• 2017

Distribution of both axial force and skin friction should be investigated in order to estimate pull-out capacity of ground anchors. Numerical method of computing load-transfer characteristics of the ground anchors, however, has not been specified and studies on this area are not sufficient. This study suggested the numerical method of simulating the characteristics of axial force and skin friction distribution against the tension type ground anchors. Also, debonding behaviors of skin friction and axial force were calculated by the suggested numerical method as a function of load levels. As a result of the review, it is confirmed that the distributions of axial force and skin friction by the suggested numerical method are relatively similar to those of field test results.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.135-148
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• 2001

In this study, an assessment method was proposed to evaluate the pullout resistance between geosynthetic and backill soil by using a stress-strain relationship of the orthotropic composite material subjected to both longitudinal and vertical loadings. For this analysis friction characteristics of geosynthetic-soil and stress-strain relationships subjected to soil confined pressure were investigated by performing the laboratory pullout tests for three types of geosynthetics and performing the confined extension tests far seven types of geosynthetics having geotextiles, composite geosynthetics and geogrids. A comparison was made between unconfined an confined moduli far each geosynthetic material to quantify the soil confinement effect on stress-strain properties. A comparison was also made between the relative increase of moduli at the same strain level among the seven geosynthetic materials to demonstrate the different responses of these geosynthetic materials under soil confinement. Based on the proposed procedure, it was shown that values of the increased tensile force are applicable fur the evaluation of friction strengths between five types of geosynthetics and sands in light of the soil confinement effect.

• Archives of design research
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• v.18 no.2 s.60
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• pp.59-68
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• 2005

This research suggests the direction realizing design business which means that designers overcome traditional role of passive design development and pursue active and subjective design development and eventually accomplish high profit by various sources except design development fee. For this, designers should be able to suggest highly successful design alternatives not by performing subjective aesthetic process but objective and scientific design development process through market-oriented information seeking, scientific design development and effective design management etc. In addition, designers should cultivates design business mind maximizing profit by various sources such as royalty, management fee and commission fee through exercising ownership, or participating distribution process and for outsourcing tasks. Regarding companies' side, they need to overcome existing manufacturing-based business paradigm focusing on rather material development, R&D, facility establishment than design or marketing, and to build design-centered business management system which menas the prior investment in design including needs identification of consumers.