• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.151-151
• /
• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.5
• /
• pp.263-269
• /
• 2017

A piezoelectric cantilever energy harvester (PCEH) driven in longitudinal (3-3) vibration mode was fabricated, and its electrical properties were evaluated by varying the resistive load. A commercial PZT piezoelectric ceramic with a high piezoelectric charge constant ($d_{33}$) of 520 pC/N and the interdigitated (IDT) electrode pattern was used to fabricate the PCEH driven in longitudinal vibration. The IDT Ag electrode embedded piezoelectric laminates were co-fired at $850^{\circ}C$ for 2 h. The 3-3 mode PCEH was successfully fabricated by attaching the piezoelectric laminates to a SUS304 elastic substrate. The PCEH exhibited a high output power of 3.8 mW across the resistive load of $100k{\Omega}$ at 100 Hz and 1.5 G. This corresponds to a power density of $10.3mW/cm^3$ and a normalized global power factor of $4.56mW/g^2{\cdot}cm^3$. Given the other PCEH driven in transverse (3-1) vibration mode, the 3-3 mode PCEH could be better for vibration energy harvesting applications.

• Childhood Kidney Diseases
• /
• v.2 no.2
• /
• pp.104-109
• /
• 1998

Purpose : The proliferative nuclear antigen Ki-67, present in all cell cycle phases except G0, is a useful marker for the detection of proliferative cells in vivo. MIB I has been found to recognize an antigen in formalin-fixed and wax-embedded material. The aim of this study was to assess the efficacy of MIB-1 expression as a marker of representing the status of mesangial cell proliferation in renal tissues. Methods : Immunohistochemical staining for Ki-67 Ag using monoclonal antibody MIB-1 (Immunotech,505) were performed in 41 renal tissuses which were obtained by percutaneous renal biopsy done between January 1994 and December 1996. Results : In both glomeruli and renal tubules, MIB-1 expression was observed only in 2 of 18 ($11.1\%$) cases of IgA nephropathy, in 2 of the 4 ($50\%$) cases of mebranoproliferative glomerulonephritis, in 4 of the 5 ($80\%$) cases of poststreptococcal glomerulonephritis. But MIB-1 expression was not detected in all cases of minimal lesion and membranous nephropathy. Renal tubules In another 7 cases of IgA nephropathy were MIB-1 positive. Conclusion : MIB-1 expression in renal tissues may relate to the cell proliferation in glomeruli and renal tubules. But the efficacy of MIB-1 expression as a marker of mesangial cell proliferation may reveal a limited value because of it's lower positive rate in IgA nephropathy.