• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.3
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• pp.161-165
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• 2007

In this paper, mesoporous Pt on micro pillars Pt electrode is newly designed, fabricated, and characterized on silicon substrate for non-enzymatic electrochemical sensor micro-chip integrated with CMOS readout circuitry. The fabricated micro/nano Pt electrode has cylindrical hexangular arrayed nano Pt pores with a diameter of 3.2 nm which is formed on top of the micro pillars Pt electrode with approximately $6{\mu}m$ in diameter, $6{\mu}m$ in space, and $50{\mu}m$ in height. The measured current responses of the fabricated plane Pt, mesoporous Pt, and mesoporous Pt on the micro pillar Pt electrodes are approximately $9.9nA/mm^2,\;6.72{\mu}A/mm^2,\;and\;7.67{\mu}A/mm^2$ in 10mM glucose solution with 0.1M phosphate buffered saline (PBS) solution, respectively. In addition, the measured current responses of the fabricated plane Pt, mesoporous Pt, and mesoporous Pt on the micro pillar Pt electrodes are approximately $0.15{\mu}A/mm^2,\;0.56{\mu}A/mm^2,\;and\;0.74{\mu}A/mm^2$ in 0.1mM ascorbic acid (AA) solution with 0.1M phosphate buffered saline (PBS) solution, respectively. This experimental results show that the proposed micro/nano Pt electrode is highly sensitive and promising for CMOS integrated non-enzymatic electrochemical sensor applications. Since the micro-pillar Pt electrode can also be utilized with a micro-fluidic mixer in the sensor chip, the sensor chip can be much smaller, cheaper, and easier to be fabricated.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.4
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• pp.301-305
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• 2009

Pt nanoparticles with a narrow size distribution (dia. ~4 nm) were synthesized via an alcohol reduction method and used for the fabrication of hybrid Pt-$SiO_2$ nanoparticles. Also, the self-assembled monolayer of Pt nanoparticles (NPs) was studied as a charge trapping layer for non-volatile memory (NVM) applications. A metal-oxide-semiconductor (MOS) type memory device with Pt NPs exhibits a relatively large memory window. These results indicate that the self-assembled Pt NPs can be utilized for NVM devices. In addition, it was tried to show the control of thin-film thickness of hybrid Pt-$SiO_2$ nanoparticles indicating the possibility of much applications for the MOS type memory devices.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.445-452
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• 2001

The purpose of this study to compare the muscle performances (peak torque (PT), relative strength (RS), average power (AP), and total work (TW)) between taping group and non-taping group after 1 hour extensive exercise. Twenty healthy male subjects were evaluated in this study. Each subject was divided with taping(n=10) and non-taping group (n=10) randomly. Muscle performances were measured at 60 degree/sec and 180 degree/sec on the Cybex 770. The PT, RS, AP, and TW were measured before and after 1 hour extensive exercise. The results showed that taping group demonstrated significantly higher PT, RS, AP, and TW during ankle dorsiflexion and plantar flexion at 60 degree/sec than those of non-taping group, except for total work during ankle plantar flexion. At the 180 degree/sec, PT and RS was significantly higher during ankle dorsiflexion and plantar flexion in taping group than in non-taping group. This results suggest that lower leg taping could be useful to maintain muscle performances during sport activities.

• Journal of the Korean Electrochemical Society
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• v.15 no.1
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• pp.12-18
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• 2012

The prohibitively high cost of Pt catalyst might be the biggest barrier for the commercialization of proton exchange membrane fuel cells (PEMFC) of which wide application is expected. Worldwide research efforts for the development of alternative to Pt oxygen reduction reaction (ORR) catalyst are made recently. One of the important considerations in the catalyst development is durability issue as well as economic aspect. From this point of view, platinum group metals (PGM) except Pt can be a candidate for replacing Pt catalyst because the material properties and the catalytic activity of PGM are expected to be similar to Pt. In contrast to Ir, Rh and Os to which not so much attention has been paid as an ORR catalyst, Pd that is most similar to Pt in terms of material properties and catalytic activity and Ru that is in the form of chalcogenide have been studied intensively. Activity comparison between non-Pt and Pt oxygen reduction catalysts by half cell test using RDE (rotating disk electrode) or PEMFC MEA (membrane electrode assembly) operation indicates that Pd-based catalysts show the most similar activity to Pt. In this paper we analyze the composition of PGM ORR catalyst in literature to promote the development of non-Pt ORR catalyst.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.241-241
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• 2010

New non-volatile memory with high density and high work-function metal nano-dots, MND (Metal Nano-Dot) memory, was proposed and fundamental characteristics of MND capacitor were evaluated. In this work, nano-dot layer of FePt with high density and high work-function (~5.2eV) was fabricated as a charge storage site in non-volatile memory, and its electrical characteristics were evaluated for the possibility of non-volatile memory in view of cell operation by Fowler-Nordheim (FN)-tunneling. Here, nano-dot FePt layer was controlled as a uniform single layer with dot size of under ~ 2nm and dot density of ${\sim}\;1.2{\times}10^{13}/cm^2$. Electrical measurements of MOS structure with FePt nano-dot layer shows threshold voltage window of ~ 6V using FN programming and erasing, which is satisfied with operation of the non-volatile memory. Furthermore, this structure provides better data retention characteristics compared to other metal dot materials with the similar dot density in our experiments. From these results, it is expected that this non-volatile memory using FePt nano-dot layer with high dot density and high work-function can be one of candidate structures for the future non-volatile memory.

• Journal of the Korean Electrochemical Society
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• v.14 no.2
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• pp.71-76
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• 2011

Fe-tetramethoxyphenylporphyrin on carbon black (Fe-TMPP/C) is examined and compared with carbon (C) and Pt-coated carbon (Pt/C) for oxygen reduction reaction in a two chambered microbial fuel cell (MFC). The Fe-TMPP/C is prepared by heat treatment and characterized using SEM, TEM, and XPS. The electrochemical properties of catalysts are characterized by voltammerty and single cell measurements. It is found that the power generation in the MFC with Fe-TMPP/C as the cathode is higher than that with Pt/C. The maximum power of the Fe-TMPP/C is 0.12 mW compared with 0.10 mW (Pt/C) and 0.02 mW (C). This high output with the Fe-TMPP/C indicates that MFCs are promising in further practical applications with low cost macrocycles catalysts.

• Korean Journal of Materials Research
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• v.27 no.3
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• pp.132-136
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• 2017

We synthesized potassium hexatitanate, ($K_2Ti_6O_{13}$, PT6), with a non-fibrous shape, by acid leaching and subsequent thermal treatment of potassium tetratitanate ($K_2Ti_4O_9$, PT4), with layered crystal structure. By controlling nucleation and growth of PT4 crystals, we obtained splinter-type crystals of PT6 with increased width and reduced thickness. The optimal holding temperature for the layered PT4 was found to be ${\sim}920^{\circ}C$. The length and width of the PT4 crystals were increased when the nucleation and growth time were increased. After a proton exchange reaction using aqueous 0.3 M HCl solution, and subsequent heat treatment at $850^{\circ}C$, the PT4 crystal transformed into splinter-type PT6 crystals. The frictional characteristics of the friction materials show that as the particle size of PT6 increases, the coefficient of friction (COF) and wear amounts of both the friction materials and counter disc increase.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.37-44
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• 2021

PURPOSE: This study examined the effects of functional electrical stimulation (FES) on temporal-spatial gait and the activities of daily living in hemiplegic stroke patients. METHODS: The subjects were 29 hemiplegic stroke patients (57.7 ± 10.3). The patients walked at a self-controlled speed in four states: (1) walking without FES (non-FES), (2) walking with FES on the gluteus medius in the stance phase (GM), (3) walking with FES on the common peroneal nerve and tibialis anterior in the swing phase (PT), (4) walking with both GM and PT. A GAITRite system, Timed-Functional Movements battery, and Timed UP and Go test were used to measure the variables. RESULTS: Significant improvements were observed in all variables of the GM+PT, GM, and PT states compared to the non-FES state (p < .05). There were significant improvements in the GM+PT state compared to GM and PT states (p < .05). Moreover, significant improvements were noted in the single support time on the affected side, backward walking 10ft, and side stepping 10ft on the affected side of the GM state compared to the PT state (p < .05). There were significant improvements in the stride length on the affected side and side stepping 10ft on the unaffected side of the PT state compared to the GM state (p < .05). CONCLUSION: FES is effective in improving the temporal-spatial gait and activities of daily living in hemiplegic stroke patients.

• Journal of Powder Materials
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• v.21 no.2
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• pp.119-123
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• 2014

Pt has been widely used as catalyst for fuel cell and exhausted gas clean systems due to its high catalytic activity. Recently, there have been researches on fabricating composite materials of Pt as a method of reducing the amount of Pt due to its high price. One of the approaches for saving Pt used as catalyst is a core shell structure consisting of Pt layer on the core of the non-noble metal. In this study, the synthesis of Pt shell was conducted on the surface of $TiO_2$ particle, a non-noble material, by applying ultraviolet (UV) irradiation. Anatase $TiO_2$ particles with the average size of 20~30 nm were immersed in the ethanol dissolved with Pt precursor of $H_2PtCl_6{\cdot}6H_2O$ and exposed to UV irradiation with the wavelength of 365 nm. It was confirmed that Pt nano-particles were formed on the surface of $TiO_2$ particles by photochemical reduction of Pt ion from the solution. The morphology of the synthesized Pt@$TiO_2$ nano-composite was examined by TEM (Transmission Electron Microscopy).

• Journal of Korean Neurosurgical Society
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• v.54 no.3
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• pp.201-206
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• 2013

Objective : To investigate the sagittal sacropelvic morphology and balance of the patients with SIJ pain following lumbar fusion. Methods : Among 452 patients who underwent posterior lumbar interbody fusion between June 2009 and January 2013, patients with postoperative SIJ pain, being responded to SIJ block were enrolled. For a control group, patients matched for sex, age group, the number of fused level and fusion to sacrum were randomly selected. Patients were assessed radiologic parameters including lumbar lordosis, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). To evaluate the sagittal sacropelvic morphology and balance, the ratio of PT/PI, SS/PI and PT/SS were analyzed. Results : A total of 28 patients with SIJ pain and 56 patients without SIJ pain were assessed. Postoperatively, SIJ pain group showed significantly greater PT (p=0.02) than non-SIJ pain group. Postoperatively, PT/PI and SS/PI in SIJ pain group was significantly greater and smaller than those in non-SIJ pain group respectively (p=0.03, 0.02, respectively) except for PT/SS (p=0.05). SIJ pain group did not show significant postoperative changes of PT/PI and SS/PI (p=0.09 and 0.08, respectively) while non-SIJ pain group showed significantly decrease of PT/PI (p=0.00) and increase of SS/PI (p=0.00). Conclusion : This study presents different sagittal sacropelvic morphology and balance between the patients with/without SIJ pain following lumbar fusion surgery. The patients with SIJ pain showed retroversed pelvis and vertical sacrum while the patients without SIJ pain have similar morphologic features with asymptomatic populations in the literature.