• Title/Summary/Keyword: Surface Activity

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Effect of erector spinae and quadratus lumborum kinesio taping and support surface conditions on abdominal muscle activity during plank exercise (플랭크 운동 시 척추세움근과 허리네모근 키네시오 테이핑 적용 및 지지면 조건이 복부 근 활성도에 미치는 영향)

  • Kim, Dong Hoon
    • Journal of Korean Physical Therapy Science
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    • v.29 no.1
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    • pp.55-63
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    • 2022
  • Background: This study investigated the effect of erector spinae and quadratus lumbar kinesio taping and support surface conditions on abdominal muscle activity during plank exercise. Design: Within-Group design. Methods: A total of twenty-three healthy men and women participated in this study. Abdominal muscle (both external obliques and internal oblique muscle) contraction was analyzed through EMG measurement with the presence or absence of kinesio taping applied to the erector spinae muscle and quadratus lumborum muscle during plank exercise and the difference between the support surfaces (stable surface and unstable surface) as variables. Abdominal EMG was attached to the right external oblique, left external oblique, right internal oblique, and left internal oblique. Results: The results showed that Abdominal left and right external obliques and internal obliques showed significant increases in activity when kinesio taping was applied to the erector spinae and quadratus lumborum muscles and unstable ground (p<0.05). Conclusion: In this study, we confirmed that the activity of the abdominal muscles was significantly increased during the plank operation in the state where the kinesio tape was attached. In addition, it was confirmed that the activity of the abdominal muscles was significantly increased during the plank operation on the unstable surface. These results suggest that in the state of kinesio tape attached and instability, plank motion has a positive effect on abdominal muscle activity.

The Interaction of Cognitive Interference, Standing Surface, and Fatigue on Lower Extremity Muscle Activity

  • Hill, Christopher M.;DeBusk, Hunter;Simpson, Jeffrey D.;Miller, Brandon L.;Knight, Adam C.;Garner, John C.;Wade, Chip;Chander, Harish
    • Safety and Health at Work
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    • v.10 no.3
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    • pp.321-326
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    • 2019
  • Background: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. Methods: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a $2{\times}2{\times}3$ within-subject repeated measures analysis of variance. Results: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. Conclusions: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.

Photocatalytic activity of various $TiO_2$ nanostructures

  • Kim, Myoung-Joo;Kim, Kwang-Dae;Tai, Wei-Sheng;Seo, Hyun-Ook;Luo, Yuan;Kim, Young-Dok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.34-34
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    • 2010
  • Activities of various $TiO_2$ nanostructures in photocatalytic decomposition of methylene blue and toluene were determined in order to shed light on the relationship between structures and photocatalytic activity. Commercially available P-25 samples were used in the present work. In addition, $TiO_2$ nanostructures were synthesized using atomic layer deposition (ALD). We show that change in the surface structure of $TiO_2$ upon variois surface treatments results in variation in photocatalytic activity. In particular, increase in the number of OH groups on the surface leads to the enhancement in photocatalytc activity. Surface OH groups increases adsorption reactivity of organic reactants, thereby increasing activity in photocatalytic decomposition of methylene blue and toluene.

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Influence of MAO Conditions on TiO2 Microstructure and Its Photocatalytic Activity (MAO 공정 변수가 TiO2 산화피막의 구조 및 광촉매 특성에 미치는 영향)

  • Kim, Jeong-Gon;Kang, In-Cheol
    • Journal of Powder Materials
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    • v.19 no.3
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    • pp.196-203
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    • 2012
  • $TiO_2$ was successfully formed on a Ti specimen by MAO (Micro-Arc-Oxidation) method treated in $Na_3PO_4$ electrolyte. This study deals with the influence of voltage and working time on the change of surface microstructure and phase composition. Voltage affected the forming rate of the oxidized layer and surface microstructure where, a low voltage led to a high surface roughness, more holes and a thin oxidized layer. On the other hand, a high voltage led to more dense surface structure, wider surface holes, a thick layer and fewer holes. Higher voltage increases photocatalytic activity because of better crystallization of the oxidized layer and good phase composition with anatase and rutile $TiO_2$, which is able to effectively separate excited electrons and holes at the surface.

Analysis of Surface Muscle Activity of Lower and Upper Musculus Erector Spinae According to Walkers form (보행기 형태에 따른 하지와 상지의 척추기립근의 표면 근활성도 분석)

  • Heo, Bo-Seob;Kim, Yong-Jae;Mun, Chae-Hwan;Son, Jae-Won;Hong, Seok-Jin
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.2
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    • pp.308-315
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    • 2014
  • The aims of this study are to analysis about surface muscle activity of lower and upper musculus erector spinae according to walkers form. The subjects of the current step is inconvenient to use a walker and five people over the age of 65 valid samples were selected as final. All the subjects were measured in three forms. Wireless EMG muscle activity is a measure of surface measurements were measured using a system, both musculus vastus lateralis, outside the erector spinae muscle, musculus biceps femoris, gastrocnemius muscle was attached to the channel electrodes. According to the results, First, gastrocnemius muscle activity showed significant differences by type of gait. Second, the muscle activity of the erector spinae muscle walking showed significant differences by type, side grip type showed the lowest muscle activity. Consequently, the present study is the efficient use of the four-wheel walker will provide the baseline data.

Investigation of Catalytic Activity Through Controlling Its Size and Composition of RhPt Bimetallic Nanoparticles (RhPt 이종금속 나노입자의 크기 및 조성 제어를 통한 촉매 활성도에 관한 연구)

  • Park, Jeong-Young;Kim, Sun-Mi
    • Journal of Powder Materials
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    • v.18 no.6
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    • pp.538-545
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    • 2011
  • This study shows that catalytic activity of bimetallic RhPt nanoparticle arrays under CO oxidation can be tuned by varying the size and composition of nanoparticles. The tuning of size of RhPt nanoparticles was achieved by changing concentration of rhodium and platinum precursors in one-step polyol synthesis. Two-dimensional RhPt bimetallic nanoparticle arrays in different size and composition were prepared through Langmuir-Blodgett thin film technique. CO oxidation was carried out on these two-dimensional nanoparticle arrays, revealing higher activity on the smaller nanoparticles compared to the bigger nanoparticles. X-ray photoelectron spectroscopy (XPS) results indicate the preferential surface segregation of Rh compared to Pt on the smaller nanoparticles, which is consistent with the thermodynamic analysis. Because the catalytic activity is associated with differences in the rates of $O_2$ dissociative adsorption between Pt and Rh, this paper suppose that the surface segregation of Rh on the smaller bimetallic nanoparticles is responsible for the higher catalytic activity in CO oxidation. This result suggests a control mechanism of catalytic activity via synthetic approaches of colloid nanoparticles, with possible application in rational design of nanocatalysts.

Activity Concentrations of 137Cs and 90Sr in Seawaters of East Sea, Korea

  • Lee, Hae Young;Kim, Wan;Kim, Yong-Hwan;Maeng, Seongjin;Lee, Sang Hoon
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.268-273
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    • 2016
  • Background: This study was a long-term evaluation of $^{137}Cs$ and $^{90}Sr$ activity concentrations in seawater samples from the East Sea, Korea, in order to establish current activity levels. Results and long-term monitoring trends will be useful in the future monitoring of environmental radioactivity. Materials and Methods: Surface seawater samples were collected quarterly from Guryongpo and Jangho in the East Coast between 1998 and 2010 and the quarterly deep seawater samples were collected from three sites in the sea adjacent to Ulleung-do between 2012 and 2015. The activity concentrations of $^{137}Cs$ were measured using a gamma-spectrometer. The activity concentrations of $^{90}Sr$ and $^{90}Y$ in a radioactive equilibrium state were measured using a gas flow proportional counter. Results and Discussion: We found the annual average activity concentrations of $^{137}Cs$ in the surface seawater was $1.66-2.89mBq{\cdot}kg^{-1}$ in Guryongpo and $1.68-2.43mBq{\cdot}kg^{-1}$ in Jangho. The annual average activity concentrations of $^{90}Sr$ in the surface seawater was $0.83-1.98mBq{\cdot}kg^{-1}$ in Guryongpo and $0.82-1.57mBq{\cdot}kg^{-1}$ in Jangho. The annual average activity concentrations of $^{137}Cs$ in the deep seawater sites were $1.51-1.73mBq{\cdot}kg^{-1}$, $1.19-1.60mBq{\cdot}kg^{-1}$ and $0.87-1.15mBq{\cdot}kg^{-1}$ in TH, JD, and HP. The annual average activity concentrations of $^{90}Sr$ in the same deep seawater sites were $1.00-1.94mBq{\cdot}kg^{-1}$, $0.82-1.26mBq{\cdot}kg^{-1}$, and $0.79-1.32mBq{\cdot}kg^{-1}$. The effective half-life was calculated by analyzing change over time in the activity concentration in the surface seawater. The effective half-life of $^{137}Cs$ was $15.3{\pm}0.1years$ in Guryongpo and $102{\pm}3years$ in Jangho. The effective half-life of $^{90}Sr$ was $28.3{\pm}4.3years$ in Guryongpo and $16.6{\pm}0.1years$ in Jangho. The ratio of the average activity concentration ($^{137}Cs/^{90}Sr$) was 1.72 in the surface seawater, which is similar to the reported ratio of the global radioactive fallout. The ratio in the deep seawater was 1.24, which is somewhat low compared to the global ratio (1.6, 1.8). Conclusion: Activity concentrations of $^{137}Cs$ and $^{90}Sr$ in the seawaters of the East Sea were similar to the previously reported activity levels in the East Sea and northwestern Pacific as a result of global radioactive fallout following atmospheric nuclear weapon tests.

The Possible Involvement of the Cell Surface in Aliphatic Hydrocarbon Utilization by an Oil-Degrading Yeast, Yarrowia lipolytica 180

  • Kim, Tae-Hyun;Oh, Young-Sook;Kim, Sang-Jin
    • Journal of Microbiology and Biotechnology
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    • v.10 no.3
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    • pp.333-337
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    • 2000
  • An oil-degrading yeast, Yarrowia lipolytica 180, exhibits interesting cell surface characteristics under the growth on hydrocarbons. An electron microscopic study revealed that the cells grown on crude oil showed protrusions on the cell surface, and thicker periplasmic space and cell wall than the cell surface, and thicker periplasmic space and cell wall than the cells grown on glucose. Y. lipolytica cells lost its cell hydrophobicity after pronase(0.1 mg/ml) treatment. The strain produced two types of emulsifying materials during the growth on hydrocarbons; one was water-soluble extracellular materials and the other was cell wall-associated materials. Both emulsifying materials at lower concentration (0.12%) enhanced the oil-degrading activity of Moraxella sp. K12-7, which had medium emulsifying activity and negative cell hydrophobicity; however, it inhibited the oil-degrading activity of Pseudomunas sp. K12-5, which had medium emulsifying activity and cell hydrophobicity. These results suggest that the oil-degrading activity of Y. lipolytica 180 is closely associated with cell surface structure, and that a finely controlled application of Y.lipolytica 180 in combination with other oil-degrading microorganisms showed a possible enhancing efficiency of oil degradation.

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The Influence of Surface Modification of Gold Nanoparticles Supported on TiO2 in the Catalytic Activity of CO Oxidation

  • Park, Da-Hee;Reddy, A.S.;Eah, Sang-Kee;Park, Jeong-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.213-213
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    • 2011
  • Gold catalysts supported on TiO2 have shown a unique catalytic behavior on CO oxidation, depending on surface effects. Particle size has an influence on the surface activity. To make monodisperse Au nanoparticles, organic capping ligands, such as alkylthiols, were used by a "greener" synthesis method [1,2] and Au nanoparticles were deposited on TiO2. However, organic capping ligands must be removed for high catalytic activities by the Au nanoparticles without changing the Au size [3]. We used UV ozone treatment to decompose thiol ligands. The samples have been characterized by X-ray photoelectron spectroscopy to examine the surface modification by UV ozone treatment. We show the size distribution of the gold nanoparticles by light scattering analysis and transmission electron microscopy. Au/TiO2 have been prepared using the wetness impregnation method. The catalytic performance of CO oxidation over Au supported on TiO2 under oxidizing reaction conditions (40 Torr CO and 100 Torr O2) were tested. The results show that the catalytic activity depends on particle size and the time of UV ozone exposure, which suggests the role of sulfur bonding in determining the catalytic activity of Au/TiO2 catalysts.

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Surface Activity of Crude Ginseng Saponin

  • Kyu, Han-Suk;Kim, Nam-Hong
    • Archives of Pharmacal Research
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    • v.7 no.2
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    • pp.109-113
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    • 1984
  • The critical micelle concentration (CMC) of crude ginseng saponin in water was determined by fluorometry and surface-tension measurement. These two methods gave the the CMC value, 0.015g/100ml AND 0.013G/100ml, respectively. The surface excess of the saponin and the area occupied by a saponin molecule at the monolayer adsorbed at air and waterinterface were calculated employing Gibbs adsorption equation. The presence of salt increased the surface activity of the saponin: it decreased the CMC, the surface tension at the CMC and the area occupied by a saponin molecule at the monolayer, which should be due to the salting-out effect of the salt.

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