• Physical Therapy Korea
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• v.24 no.1
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• pp.61-70
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• 2017

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 cm) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

• Physical Therapy Korea
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• v.25 no.3
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• pp.1-11
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• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.104-114
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• 1994

ZrO2 fibers were fabricated by means of the Sol-Gel process using Zr(O-nC3H7)4-H2O-C2H5OH-HNO3 solution as a starting material. The optimum experimental parameters such as molar ratio of starting materials, concentration, temperature, viscosity, the amounts of stabilizer and the pH of solution were determined. The experimentally determined optimum variables which produce good ZrO2 fibers were used to manufacture the Y2O3-and CaO-ZrO2 fibers. The amounts of Y2O3 and CaO were varied within the range from 1.5~5 mol% and 3~15 mol% respectively. The phase transformation and microstructural evolution of the fabricated ZrO2 gel fibers were investigated after heat treatments up to 120$0^{\circ}C$ by X-ray diffraction, Raman microprobe spectroscopy, SEM, and specific surface area and pore volume measurements. From the analysis of X-ray diffraction and Raman spectra, the phase of heat treated Y2O3-and CaO partially stabilized ZrO2 gel fibers(Y2O3:2.5~3 mol%, CaO:6~9 mol%) were identified as a tetragonal phase up to 100$0^{\circ}C$. The maximum tensile strength of 2.5Y2O3-97.5ZrO2 and 6CaO-94ZrO2 (in mol%) fibers heat treated at 100$0^{\circ}C$ for 1 hr was found be 1.3~2 GPa with diameters of 10~20 ${\mu}{\textrm}{m}$.

• Journal of the Korean Ceramic Society
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• v.53 no.6
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• pp.604-609
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• 2016

This study reports on wet-foam stability with respect to porous ceramics from a particle-stabilized colloidal suspension that is achieved through the addition of polymethyl methacrylate (PMMA) using a wet process. To stabilize the wet foam, an initial colloidal suspension of $Al_2O_3$ was partially hydrophobized by the surfactant propyl gallate (2 wt.%) and $SiO_2$ was added as a stabilizer. The influence of the PMMA content on the bubble size, pore size, and pore distribution in terms of the contact angle, surface tension, adsorption free energy, and Laplace pressure are described in this paper. The results show a wet-foam stability of more than 83%, which corresponds to a particle free energy of $2.7{\times}10^{-12}J$ and a pressure difference of 61.1 mPa for colloidal particles with 20 wt.% of PMMA beads. It was possible to control the uniform distribution of the open/closed pores by increasing the PMMA content and by adding thick struts, leading to the achievement of a higher-stability wet foam for use in porous ceramics.

• Polymer(Korea)
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• v.36 no.1
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• pp.104-110
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• 2012

The dispersion of pigment particles is important because it is capable of increasing the color strength, contrast, and transmittance of color-LCD products. Pigment dispersion properties are very important factors for the quality of LCD color filters. The chemical structure of polymeric dispersants for pigment is important to improve dispersion stability and prevent aggregation or flocculation of pigment in organic or aqueous systems. Polymeric dispersants should contain both anchoring group that interacts with pigment surface and stabilizing group that provides steric stabilization. Moreover, the molecular weight and composition of block copolymer have the an effect on pigment dispersion. In this study, adequate dispersants, block copolymers containing (2-dimethylamino)ethyl methacrylate as anchoring group and oligo(ethylene oxide)methyl ether methacrylate as a stabilizing group were designed and synthesized by atom transfer radical polymerization in order to prepare well-defined structure, molecular weight and composition.

• Environmental Engineering Research
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• v.24 no.3
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• pp.463-473
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• 2019

Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.4
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• pp.91-100
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• 2018

Purpose : The study investigated the effects of Pilates exercise on strengthening trunk muscles of females who perform such exercise for the purpose of comparing activation of trunk muscles that contact while performing Pilates motions between females with or without at least 8 weeks of Pilates experience. Methods : The study investigated 10 females with at least 8 weeks of Pilates experience in the past 6 months (experienced group) and 10 healthy females without Pilates experience (non-experienced group). The study used basic Pilates postures involving hip abduction, lift, and leg swing motions as the measurement postures in comparing the activation of muscles used for stabilization, such as the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles. Surface electromyography was used for measuring muscle activation, and the measurements targeted activation of the rectus abdominis, external oblique abdominal, transversus abdominis, and internal oblique abdominal muscles. Results : The study results showed that, as compared to the non-experienced group, the experienced group had significantly higher muscle activation in the transverse abdominis and internal oblique abdominal muscles during hip abduction (p<.05) and significantly higher muscle activation in the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles during lift and leg swing motions (p<.05). Conclusion : Pilates exercise performed over a long period can be recommended as an effective exercise method that can increase the activation of trunk muscle, and especially, repeated performance of highly difficult motions can increase muscle activation even more, which can help promote spinal stabilization, prevent pain, and improve performance of activities of daily living.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.17-22
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• 2019

BACKGROUND: Soil contamination of As is a very sensitive environmental issue due to its adverse impact on human health and different characteristics with other heavy metals. With public awareness of As poisoning, there has been growing interest in developing guideline and remediation technologies for As-contaminated soil. The objective of this research was to evaluate the effectiveness of stabilizing amendments and soil dressing methods on the mobility of As in the contaminated rice paddy soils nearby mining area. METHODS AND RESULTS: Different amendments were mixed with surface and subsurface contaminated soils at a ratio of 3% (w/w) and monitored for five months. Three different extractants including 0.01M $CaCl_2$, TCLP, and PBET were used to examine As bioavailability in the soil and the concentration of As in rice grain was also measured with an inductively coupled plasma (ICP) spectroscopy. The results showed that all amendment treatments decreased As concentration compared to the control. Especially, coal mine drainage sludge (CMDS) treatment showed the highest efficiency of decreasing As concentration in the soil and rice grain. The values of Pearson correlation (r) between As concentrations in the soil and rice grain were 0.782, 0.753, and 0.678 for $CaCl_2$, TCLP, and PBET methods, respectively. Especially, $CaCl_2$ method was highly correlated between As concentrations of the soil and soil solution (r=0.719), followed by TCLP (r=0.706), PBET (r=0.561) methods. CONCLUSION: Stabilizing amendments can effectively reduce available As concentration in the soils as well as soil solution, and thereby potentially mitigating risks of crop contamination by As.

• Clean Technology
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• v.19 no.1
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• pp.38-43
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• 2013

Vapor adsorption of hydrocarbon has been studied for stabilization after drying low-rank coal. The surface characteristics and the propensity of spontaneous combustion were observed for stabilized coal which was maintained with hydrocarbons as stabilizer at several conditions of residence time and temperature. Surface area of micropores in coal mainly decreased after vapor adsorption. As residence time and temperature of adsorption process increased, the propensity of spontaneous combustion decreased. The type of hydrocarbons did not effect on the propensity of spontaneous combustion. As the analysis results of this work, the amount of hydrocarbon adsorbates required to stabilize dried coal was 0.5 wt% or less of coal, and the stabilizing effect was induced by adsorption of low-molecular-weight hydrocarbons.

• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.190-197
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• 2012

We employed the vinyl ethylene carbonate (VEC) as an electrolyte additive and investigated the effect of the electrolyte additive on the electrochemical performance in hybrid capacitor. The activated carbon was adopted as cathode material, and the $Li_4Ti_5O_{12}$ oxide was used as anode material. The electrolyte was prepared with the $LiPF_6$ salt in the mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate(EMC). We evaluated the electrochemical performance of the hybrid capacitor with increasing the amount of the VEC electrolyte additive, which is known as the remover of oxygen functional group and the stabilizer of the electrode by reducing the surface of electrode, and obtained the superior performance data especially at the addition of the VEC electrolyte additive of around 0.7 vol%. On the contrary, the addition of the VEC more than 0.7 vol% in the electrolyte leads to the degradation in electrochemical performance of hybrid capacitor, suggesting the increase of the side reaction from the excessive VEC additive. X-ray photoelectron spectroscopy (XPS) revealed that the addition of the VEC suppressed the formation of LiF component, which is known as the insulator, on the surface of electrode. The optimized addition of VEC exhibited the improved capacity retention around 82.7% whereas the bare capacitors without VEC additive showed the 43.2% of capacity retention after 2500 cycling test.