• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.197-197
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• 2011

In this study, in contrast with cases in which Scanning Tunneling Microscopy (STM) tip-induced reactions were instigated by the tunneling electrons, the local electric field, or the mechanical force between a tip and a surface, we found that the tungsten oxide (WO3) covered tungsten (W) tip of a STM acted as a chemical catalyst for the S-H dissociative adsorption of phenylthiol and 1-octanethiol onto a Ge(100) surface. By varying the distance between the tip and the surface, the degree of the tip-catalyzed adsorption could be controlled. We have found that the thiol head-group is the critical functional group for this catalysis and the catalytic material is the WO3 layer of the tip. After removing the WO3 layer by field emission treatment, the catalytic activity of the tip has been lost. 3-mercapto isobutyric acid is a chiral bi-functional molecule which has two functional groups, carboxylic acid group and thiol group, at each end. 3-Mercapto Isobutyric Acid adsorbs at Ge(100) surface only through carboxylic acid group at room temperature and this adsorption was enhanced by the tunneling electrons between a STM tip and the surface. Using this enhancement, it is possible to make thiol group-terminated surface where we desire. On the other hand, surprisingly, the WO3 covered W tip of STM was found to act as a chemical catalyst to catalyze the adsorption of 3-mercapto isobutyric acid through thiol group at Ge(100) surface. Using this catalysis, it is possible to make carboxylic acid group-terminated surface where we want. This functional group-selective adsorption of bi-functional molecule using the catalysis may be used in positive lithographic methods to produce semiconductor substrate which is terminated by desired functional groups.

• 국제물리치료학회지
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• 제10권2호
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• pp.1756-1762
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• 2019

Background: Functional ankle instability (FAI) indicating a decrease in muscle strength, proprioception, neuromuscular control, balance and postural control function. Objective: To investigate the effect of jumping exercise on the supporting surface on the ankle muscle thickness, proprioceptive sensation, and balance in adults with FAI. Design: Randomized Controlled Trial. Methods: Twenty young people with FAI were randomly assigned to the unstable supporting surface jump group (N=10) and the stable supporting surface jump group (N=10). The intervention was conducted three times a week for eight weeks, and for 30 minutes per session. Trampoline was used as an unstable support surface and the stable support surface was carried out on a regular floor. The thickness of the tibialis anterior muscle and medial gastrocnemius muscle was measured by ultrasonography, and the proprioception of dorsiflexion and plantarflexion was measured using an electrogoniometer. The dynamic balance was also measured with a balance meter. Results: The the muscle thickness of the medial gastrocnemius muscle was significantly higher in the stable supporting surface jump group than in the unstable supporting surface jump group (p<.05). Furthermore, the plantar flexion proprioception and dynamic balance were significantly improved in the unstable supporting surface jump group than in the stable supporting surface jump group in the intergroup comparison (p<.05). Conclusions: The conclusion has been reached in this study that the jumping exercise on the unstable supporting surface could be a more effective in improving FAI than the regular surface.

• The Journal of Korean Physical Therapy
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• 제28권4호
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• pp.254-258
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• 2016

Purpose: This study was conducted to identify the effects of dual task training on balance and functional performance in high school soccer players with functional ankle instability. Methods: Twenty high school soccer players with functional ankle instability were randomly assigned to a single task training group and a dual task training group. One participant who did not participate regularly in the training was excluded. The single task training group (n=9) received balance training on an unstable surface. The dual task training group (n=10) received balance training on an unstable surface and had to catch thrown balls during the balance training. Both groups were trained for 4 weeks, 3 days a week. The balance and functional performance of both groups was measured before and after training. Balance was measured using an anterior-posterior and medio-lateral balance. Functional performance was measured based on a figure-of-8 hop test, up-down hop test, and a single hop test. All data were analyzed by repeated two-way ANOVA tests. Results: A time by group interaction effect was not observed in the medio-lateral balance test, figure-of-8 hop test, or single hop test (p>0.05). A time by group interaction effect was observed in the anterior-posterior balance and up-down hop test (p<0.05). Conclusion: These results suggest that dual task training improved balance and functional performance better than single task training for some items.

• 대한정형도수물리치료학회지
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• 제20권2호
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• pp.1-7
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• 2014

Purpose: The purpose of this study was to compare the effects of the balance training on the stable and unstable supporting surfaces for the subjects with functional ankle instability. Methods: Twenty-nine subjects with functional ankle instability were randomly assigned to the stable group (n=14) and the unstable group (n=15). Balance training was conducted twenty minutes a day on the stable surface for the stable group and on the airostep for the unstable group three times a week for four weeks. Balance training program was consisted of ten steps by eye opened or closed and two or one leg standing. X-speed for transverse balance and Y-speed for longitudinal balance were measured with eye opened and closed in affected leg standing position. Results: There were significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01) in stable group. Unstable group also showed significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01). There were no statistical differences in the magnitude of improvement between the groups (p<.05). Conclusions: Based on such results, it can be said that balance training on the stable surface is effective as much as training on the unstable surface for the subjects with functional ankle instability.

• Environmental Engineering Research
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• 제24권1호
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• pp.173-179
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• 2019

Prussian blue (PB) is known to be an effective material for radioactive cesium adsorption, but its nano-range size make it difficult to be applied for contaminated water remediation. In this study, a simple and versatile approach to immobilize PB in the supporting matrix via surface functionalization was investigated. The commercially available poly vinyl alcohol (PVA) sponge was functionalized by acrylic acid (AA) to change its major functional group from hydroxyl to carboxylic, which provides a stronger ionic bond with PB. The amount of AA added was optimized by evaluating the weight change rate and iron(III) ion adsorption test. The FTIR results revealed the surface functional group changing to a carboxyl group. The surface functionalization enhanced the attachment of PB, which minimized the leaching out of PB. The $Cs^+$ adsorption capacity significantly increased due to surface functionalization from 1.762 to 5.675 mg/g. These findings showed the excellent potential of the PB-PAA-PVA sponge as a cesium adsorbent as well as a versatile approach for various supporting materials containing the hydroxyl functional group.

• Corrosion Science and Technology
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• 제17권2호
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• pp.74-80
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• 2018

The electronic industries require environmentally-friendly and highly functional materials to enhance the quality of human life. Home appliances require insect repellent steels that work to protect household microwave ovens from incurring damage by insects such as fire ants and cockroaches in tropical regions. Thus, POSCO has developed new types of functional steels, coated with an array of organic-inorganic hybrid composites on the steel surface, to cover panels in microwave ovens and refrigerators. The composite solution uses a fine dispersion of hybrid solution with polymeric resin, inorganic and a pyrethroid additive in aqueous media. The hybrid composite solution coats the steel surface, by using a roll coater and is cured using an induction curing furnace on both the continuous galvanizing line and the electro-galvanizing line. The new steels were evaluated for quality performances, salt spray test for corrosion resistance and biological performance for both insect repellent and antimicrobial activity. The new steels with organic-inorganic composite coating exhibit extraordinarily biological functionalities, for both insect repellent and antimicrobial activities for short and long term tests. The composite-coating solution and experimental results are discussed and suggest that the molecular level dispersion of insecticide on the coating layer is key to biological functional performances.

• 대한환경공학회지
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• 제29권3호
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• pp.357-364
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• 2007

본 연구는 폐타이어의 재활용 일환으로 기존의 분말 화된 폐타이어 표면에 특정의 Functional group을 형성시켜 수중의 중금속이온들 과의 Chelate complexes 형성을 유도 함으로서 중금속 제거제로서의 폐타이어 활용방안을 제시 하고자 하였다. 이를 위해 FT-IR을 통하여 Function리 group의 종류 및 XRD, XRF, SEM 용출실험을 통해 개질 변화된 폐타이어 특성 분석하였으며 Kinetics Study를 통해 흡착모델에 적용하여 특정상수 값을 도출 하였다. 결과적으로 중금속 흡착 선호도는 $Pb^{2+}>Cu^{2+}>Cd^{2+}$순으로 확인되었으며, 초기 30분 이내에 흡착평형에 도달 하였고, 흡착반응속도 또한 0.27에서 $1.78\sim3.15(g/mg{\cdot}min)$로 증가하였으며, 80% 이상의 제거효율을 보였다. 이는 기존의 분말폐타이어에 비해 그 효율이 10배가량 증가함을 알 수 있었으며, Functional group을 활용한 폐타이어를 이용할 경우 중금속제거제로서의 뛰어난 효율성을 제시 할 수 있었다.

• 한국전문물리치료학회지
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• 제15권4호
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• pp.18-26
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• 2008

The present study was aimed at investigating the postural control ability of volleyball players with functional ankle instability. The subjects were 26 male volleyball players were divided into 2 groups (13 subjects with functional ankle instability and 13 subjects with ankle stability) who could evaluate Questionnaire. All the male participants were tested by a Balance Master System. This study were to measure of static balance ability, dynamic balance ability, motor function the difference between functional ankle instability group and control group. Ankle instability group and stable group in postural sway ($^{\circ}/sec$) on film surface with eye closed in modified clinical test sensory interaction on balance, and left unilateral stance with eye opened and closed were significantly different (p<.05). The ankle instability group and stable group in limit of stability were significantly different (p<.05). The ankle instability group and stable group in left/right rhythmic weight shirt were significantly different (p<.05). The ankle instability group and stable group in turn time (sec) & turn sway ($^{\circ}$) during step/quick turn and end sway ($^{\circ}/sec$) in tandem walk were significantly different (p<.05). This study showed that volleyball players with functional ankle in stability were effected postural control ability by static balance & dynamic balance ability. Further study is needed to measure various athletic with functional ankle instability for clinical application.

• 한국결정성장학회지
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• 제6권4호
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• pp.648-662
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• 1996

임피던스 스펙트럼을 이용하여 황산 용액에서 glassy carbon과 인조흑연(PVDF 합성 흑연)의 전극표면에 cyclic 분극을 부하 하였을 경우 전극표면에서 나타나는 표면반응에 대하여 조사하여 . 두 재료 표면에서 산소의 산화 혹은 환원과 관련되거나 또는 탄소재료 표면에 화학흡착된 표면작용기(surface functional group)의 변화와 관련되는 것으로 생각되는 산화환원 피크가 potentio-dynamic곡선에서 나타났다. 이러한 전극 표면에서의 표면작용기의 산화환원은 glassy carbon과 PVDF합성 흑연의 임피던스 스펙트럼에도 커다란 영향을 미치는 것으로 나타났다. 또 glassy carbon과 PVDF합성 흑연에서의 임피던스 파라미터는 분극부하에의해 현저한 변화가 나타났다.가 나타났다.

• The Journal of Korean Physical Therapy
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• 제28권3호
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• pp.189-194
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• 2016

Purpose: This study focuses on influence of ankle stabilization training on balance ability and lower limb muscle activation of soccer player with functional ankle instability. Methods: Subjects were grouped into ankle stabilization training group using biofeedback comprised of 15 subjects and general exercise group of 15. The training was conducted for 30 minutes, 3 times a week for 8 weeks in total. All 30 football players conducted plyometric training for 30 minutes before main training. To evaluate balance ability, biorescure was used to measure whole path length and surface area and surface electromyography (EMG) system was used to measure tibialis anterior, tibialis posterior, and soleus to evaluate lower limb muscle activation. Results: The experiment group showed significant difference to the comparison group in regard of whole path length and surface area which represents balancing capability and muscle activation of tibialis anterior, tibialis posterior, and soleus. Conclusion: Therefore, ankle stabilization training using biofeedback is more effective in enhancing balance ability and lower limb muscle activation than general exercise.