• Transactions of the Korean hydrogen and new energy society
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• v.9 no.1
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• pp.25-30
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• 1998

4-probe resistivity measurement technique was used to study kinetics of hydrogen absorption on Pd film ($180{\AA}$ thick) in the ${\alpha}$ phase. Hydrogen gas was introduced to the activated Pd film. For very low hydrogen concentration the following rate law is valid in ${\alpha}$ phase very thin Pd film $$v=k\frac{1}{1+KX{_H}}PH{_2}-k^{\prime}\frac{KX{_H}{^2}}{1+KX{_H}}$$ which is similar to that of bulk. The activation energy of the forward reaction is 4.6kcal/mol H and of the backward reaction 8.4kcal/mol H, which yields the reaction enthalpy -3.8kcal/mol H in the temperature range between 25 and $40^{\circ}C$. The values of activation and enthalpy of thin film are rather smaller than that of bulk sample. This may be due to surface area difference between bulk and film.

• Physical Therapy Korea
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• v.27 no.3
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• pp.206-211
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• 2020

Background: The longitudinal arch is important for individuals with pes planus. The toe spread out exercise (TSO) has been widely used to continuously support the longitudinal arch by increasing the abductor hallucis (AbdH) muscle activation. However, the AbdH muscle is commonly lack of the sufficient activation during the TSO especially in individuals with pes planus. Objects: This study was performed to investigate the effect of arch support on the muscle activity and strength of the AbdH during TSO in standing position in individuals with pes planus. Methods: Twenty subjects with pes planus between 20 and 30 years of age participated in this study. The muscle activity and strength of the AbdH were measured using surface EMG system and the Smart KEMA tensiometer system. The AbdH muscle was evaluated during TSO between individuals with and without longitudinal arch support in standing position. The longitudinal arch was supported by using the insole. The paired t-test was used. The level of statistical significance was set at α = 0.05. Results: The muscle activity and strength of the AbdH during TSO with arch support in standing position was significantly greater than that without arch support. Conclusion: The muscle activity and strength of the AbdH during TSO in standing position can be influenced by the longitudinal arch support in individuals with pes planus. The AbdH strengthening during TSO in standing with arch support can be recommended especially in individuals with pes planus in the clinical settings.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1087-1095
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• 2003

Betulinic acid (BA), a pentacyclic triterpene isolated from Lycopus lucidus, has been reported to be a selective inducer of apoptosis in various human cancer and shown anti-inflammatory and immunomodulatory properties. We postulated that BA modulates the immunomodulatory properties at least two groups of protein mediators of inflammation, interlukin-1$\beta$ (IL-1$\beta$) and the tumor necrosis factor- $\alpha$ (TNF-$\alpha$) on the basis of the critical role of the monocytes and tissue macrophages in inflammatory and immune responses. TNF-$\alpha$ and IL-1$\beta$ were produced by BA in a dose dependent manner at concentration of 0.625 and 10 $\mu$g/mL. The production of NO associated with iNOS was inhibited when treated with LPS at the concentration of 2.5 to 20 $\mu$g/mL of BA whereas COX-2 expression was decreased at 2.5 to 20 $\mu$g/mL. These modulations of inflammatory mediators were examined in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The morphology of macrophage was also examined and enhanced surface CD 40 molecule was expressed when treated BA at 0.625∼5 $\mu$g/mL with or without LPS. Furthermore, BA (20 $\mu$g/mL) enhanced apoptosis by producing DNA ladder in the RAW 264.7 cells. Our results indicated that BA induced activation of macrophage and pro-inflammatory cytokines. This may provide a molecular basis for the ability of BA to mediate macrophage, suppress inflammation, and modulate the immune response.

• Korean Journal of Materials Research
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• v.23 no.10
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• pp.580-585
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• 2013

To observe the formation of defects at the interface between an oxide semiconductor and $SiO_2$, ZnO was prepared on $SiO_2$ with various oxygen gas flow rates by RF magnetron sputtering deposition. The crystallinity of ZnO depends on the characteristic of the surface of the substrate. The crystallinity of ZnO on a Si wafer increased due to the activation of ionic interactions after an annealing process, whereas that of ZnO on $SiO_2$ changed due to the various types of defects which had formed as a result of the deposition conditions and the annealing process. To observe the chemical shift to understand of defect deformations at the interface between the ZnO and $SiO_2$, the O 1s electron spectra were convoluted into three sub-peaks by a Gaussian fitting. The O 1s electron spectra consisted of three peaks as metal oxygen (at 530.5 eV), $O^{2-}$ ions in an oxygen-deficient region (at 531.66 eV) and OH bonding (at 532.5 eV). In view of the crystallinity from the peak (103) in the XRD pattern, the metal oxygen increased with a decrease in the crystallinity. However, the low FWHM (full width at half maximum) at the (103) plane caused by the high crystallinity depended on the increment of the oxygen vacancies at 531.66 eV due to the generation of $O^{2-}$ ions in the oxygen-deficient region formed by thermal activation energy.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.439-447
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• 2013

Time-temperature integrators (TTIs) are simple and cost-efficient tools which may be used to predict food quality. Enzymatic TTIs are devised to indicate food quality in the form of color alterations from green to red, based on the cumulative impacts of temperature and time period on the enzymatic reactions. In this study, the quality of ground beef patties was investigated for the parameters of pH levels, color, VBN, water holding capacity, and total microbial counts, depending on various storage temperatures (5, 15, and $25^{\circ}C$). TTIs were attached to the surface of the ground beef patties in order to evaluate the degree of correlating colorimetric changes with the determined quality parameters. Through the Arrhenius equation, activation energy and constant reaction rates of TTI, VBN, and total microbial counts were calculated as to observe the relationship between enzymatic reactions of the TTI and food spoilage reactions of the ground beef patties. VBN and total microbial counts were already increased to reach decomposition index (VBN: 20, total microbial count: 7-8 Log CFU/g) of meat at middle stage of storage period for each storage temperature. Although activation energy of TTI enzymatic reactions and food spoilage reactions of the ground beef patties were similar, the change of TTI color was not a coincidence for food spoilage at $5^{\circ}C$ and $15^{\circ}C$ of storage temperature. It was suggested that TTI should be designed individually for storage temperature, time, type of meat, or decomposition index of meat.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.323-323
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• 2013

High power light-emitting diodes (LEDs) are widely used in many device applications due to its ability to operate at high power and produce high luminance. However, releasing the heat accumulated in the device during operating time is a serious problem that needs to be resolved to ensure high optical efficiency. Ceramic or Aluminium base metal printed circuit boards are generally used as integral parts of communication and power devices due to its outstanding thermal dissipation capabilities as heat sink or heat spreader. We investigated the characterisation of electroless plating of Ni-B film according to plating bath temperature, ranging from $50^{\circ}C$ to $75^{\circ}C$ on Ag paste/anodised Al ($Al_2O_3$)/Al substrate to be used in metal PCB for high power LED packing systems. X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FE-SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in the film analysis. By XRD result, the structure of the as deposited Ni-B film was amorphous irrespective of bath temperature. The activation energy of electroless Ni-B plating was 59.78 kJ/mol at the temperature region of $50{\sim}75^{\circ}C$. In addition, the Ni-B film grew selectively on the patterned Ag paste surface.

• Journal of Powder Materials
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• v.25 no.4
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• pp.322-326
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• 2018

The hydrogen reduction behavior of $MoO_3-CuO$ powder mixture for the synthesis of homogeneous Mo-20 wt% Cu composite powder is investigated. The reduction behavior of ball-milled powder mixture is analyzed by XRD and temperature programmed reduction method at various heating rates in Ar-10% $H_2$ atmosphere. The XRD analysis of the heat-treated powder at $300^{\circ}C$ shows Cu, $MoO_3$, and $Cu_2MoO_5$ phases. In contrast, the powder mixture heated at $400^{\circ}C$ is composed of Cu and $MoO_2$ phases. The hydrogen reduction kinetic is evaluated by the amount of peak shift with heating rates. The activation energies for the reduction, estimated by the slope of the Kissinger plot, are measured as 112.2 kJ/mol and 65.2 kJ/mol, depending on the reduction steps from CuO to Cu and from $MoO_3$ to $MoO_2$, respectively. The measured activation energy for the reduction of $MoO_3$ is explained by the effect of pre-reduced Cu particles. The powder mixture, hydrogen-reduced at $700^{\circ}C$, shows the dispersion of nano-sized Cu agglomerates on the surface of Mo powders.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.2
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• pp.33-37
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• 2010

Purpose : We investigated the effects of the insole types on lower leg muscle activation during treadmill walking. The three insole types investigated for this study were normal insole, medial wedge insole, and viscoheel. Methods : Participants were assigned into three groups. People with foot transformation were excluded from this study. Each participant walked for ten minutes. The first day we applied a normal insole. On the second day, a medial wedge insole was applied. Finally, on the last day a viscoheel was applied. After walking on a treadmill for ten minutes, we measured muscle activation in lower leg muscles (gastrocnemius and tibialis anterior). Surface electromyography (EMG) was used to measure muscle activity. The data were analyzed using one-way analysis of variance (ANOVA) with repeated measures to determine the statistical significance. Results : The results of this study were summarized as follows. While walking on the treadmill, root mean square (RMS) values of the gastrocnemius when the viscoheel was applied were significantly lower than the other insole types. There was no significant difference for the RMS values for the tibialis anterior using viscoheel. The normal insole and viscoheel insole were significantly different in a post hoc analysis. However, there was no significant difference for normal insole and medial wedge insole. Conclusion : Using a viscoheel insole decreases muscle activity of the lower leg. Therefore, in conclusion, the viscoheel insole type reduces the load on the lower leg during walking.

• Physical Therapy Korea
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• v.25 no.3
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• pp.51-59
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• 2018

Background: Despite muscle latency times and patterns were used as broad examination tools to diagnose disease and recovery, previous studies have not compared the dominant arm to the non-dominant arm in muscle latency time and muscle recruitment patterns during reaching and reach-to-grasp movements. Objects: The present study aimed to investigate dominant and non-dominant hand differences in muscle latency time and recruitment pattern during reaching and reach-to-grasp movements. In addition, by manipulating the speed of movement, we examined the effect of movement speed on neuromuscular control of both right and left hands. Methods: A total of 28 right-handed (measured by Edinburgh Handedness Inventory) healthy subjects were recruited. We recorded surface electromyography muscle latency time and muscle recruitment patterns of four upper extremity muscles (i.e., anterior deltoid, triceps brachii, flexor digitorum superficialis, and extensor digitorum) from each left and right arm. Mixed-effect linear regression was used to detect differences between hands, reaching and reach-to-grasp, and the fast and preferred speed conditions. Results: There were no significant differences in muscle latency time between dominant and non-dominant hands or reaching and reach-to-grasp tasks (p>.05). However, there was a significantly longer muscle latency time in the preferred speed condition than the fast speed condition on both reaching and reach-to-grasp tasks (p<.05). Conclusion: These findings showed similar muscle latency time and muscle activation patterns with respect to movement speeds and tasks. Our findings hope to provide normative muscle physiology data for both right and left hands, thus aiding the understanding of the abnormal movements from patients and to develop appropriate rehabilitation strategies specific to dominant and non-dominant hands.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.551-555
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• 2012

Desorption reaction characteristics of the commercial activated carbons which were used for the removal of industrial odorants were investigated. BET specific surface area was analyzed to investigate the chemicophysical property of activated carbon. Adsorptivity of activated carbon was estimated by iodine number. Thermogravimetric analyzer (TGA) was used to investigate the desorption characteristics. Activation energies and reaction orders for reaction characteristics according to adsorption and desorption of activated carbons were estimated by employing the Friedman method and Freeman-Carroll method. Adsorptivity of reprocessed activated carbons were significantly lower than that of fresh activated carbons. In this study, it was found that the activation energies were 15.9~23.4 kJ/mol in Friedman method and 22.7~33.8 kJ/mol in Freeman-Carroll method.