• Archives of Plastic Surgery
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• v.38 no.2
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• pp.155-160
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• 2011

Purpose: Fibrillar collagens like type I collagen, are the major constituent of the extracellular matrix and structural protein of bone. Also, it can be a scaffold for osteoblast migration. The purpose of this study is to estimate the effects of absorbable atelo-collagen sponge (Teruplug$^{(R)}$, Terumo biomaterials Co., Tokyo, Japan) insertion in tooth extraction sites on periodontal healing of the second molar, healing of the fractured mandibular bone and new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Methods: In our study of six cases of mandibular angle fractures, all of them underwent the extraction of the third molar tooth & absorbable atelo-collagen sponge insertion in tooth extraction site. Three of them had a intraoral infection & oral opening to fracture site, two of the six had dental caries, and only one had reduction problem due to third molar position. Six consecutive patients with noncomminuted fractures of the mandibular angle were treated by open reduction and internal fixation using one noncompression miniplates and screws placed through a transoral incision. Results: All of the patients have showed good postoperative functions and have not experienced complications requiring second surgical intervention. There was well healing of the mandibular bone and the most new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Conclusion: The results of this study suggest that absorbable atelo-collagen sponge is relatively favorable bone void filler with prevention of tissue collapse, food packing, and enhance periodontal healing. Thus, the use of atelo-collagen sponge and one noncompression miniplate seems to be relatively easy, safe, and effective for the treatment of fractures of the mandibular angle and third molar extraction.

• Applied Biological Chemistry
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• v.18 no.4
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• pp.194-202
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• 1975

This study was conducted to study the properties of the water-soluble natural chelating agents from garbage compost and activated sewage sludge responsible for Fe chelation, which is closely associated with the effectiveness in correcting iron chlorosis in plant. The water-soluble fraction of these materials was fractionated by menas of Sephadex gel filtration and the fractions of Fe chehates were traced by radioactive $^{59}Fe$. The fractions were examined by ultraviolet and infrared. spectroscopy and stability constants for Fe. The water-soluble fraction from garbage compost was separated by Sephadex G-25 into approximately four fractions. Most of the added $^{59}Fe$ was associated with fraction I, which appeared at the void volume. Further fractionation by Sephadex G-50 indicated that the molecular weight of water-soluble chelating agents is in the approximate range of 5000 to 10,000. The water-soluble fraction from activated sewage sludge gave six fractions by Sephadex G-25. Most of the added $^{59}Fe$ was found in the fraction I,II, and III, The molecular weights of most chelating agents associated with $^{59}Fe$ appeared to be less than 5,000 and those of fraction I that appeared at the void volume was in the range of 5,000 to 1,000. Discrepancy between radio activity count and UV absorption indicated the heterogeneity of the fractions obtained by Sephadex gel filtration. Ultraviolet absorption spectra of all fractions separated by Sephadex G-25 and containing chelating agents showed no differences. Fraction IV and V of sewage extract showed absorption maxima and shifting similar to nucleic acid components suggesting the presence of decomposition products of nucleic acid. Similarity fraction VI contained phenolic type amino acid groups. Fraction I of compost extract contained most of the added $^{59}Fe$ and showed weak but extra definite absorption in the 1230, and $1270cm^{-1}$ region, suggesting that extra oxygen groups in polyphenolic structure were probably involved in Fe chelation. In sewage extract, fraction I,II, and III in which most of the $^{59}Fe$ was found, showed strong definite polypeptide absorption in the region of $1540cm^{-1}$ due to NH deformation and C-N stretching of amide groups in the peptidebond. These extra functional groups in fraction I, II, and III appeared to be associated with Fe chelation. The other fractions, not associated with $^{59}Fe$, still have carboxyl and hydroxyl groups, suggesting that these functional groups in these water extracts may not independently form the Fe chelates. Precipitation of ferric hydroxide precluded measuring the stability constants for Fe-chelates. However, the formation constants for Zn chelates as log K values for compost extract and sewage extract at pH 4.0 from which the strength of chelation with Fe could be presumed, were 8.23, and 9.75, respectively, indicating strong complexation with metals. The chelating capacity of compost extract containing 6.5 g organic matter per liter was 0.82 mM, and that of sewage extract containing 5.3 g per liter was 0. 64 mM.

• Journal of the Korean Vacuum Society
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• v.14 no.2
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• pp.91-96
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• 2005

The silicon-on-insulator (SOI) wafer fabrication technique has been developed by using ion-cut process, based on proton implantation and wafer bonding techniques. It has been shown by SRIM simulation that 65keV proton implantation is required for a SOI wafer (200nm SOI, 400nm BOX) fabrication. In order to investigate the optimum proton dose and primary annealing condition for wafer splitting, the surface morphologic change has been observed such as blistering and flaking. As a result, effective dose is found to be in the $6\~9\times10^{16}\;H^+/cm^2$ range, and the annealing at $550^{\circ}C$ for 30 minutes is expected to be optimum for wafer splitting. Direct wafer bonding is performed by joining two wafers together after creating hydrophilic surfaces by a modified RCA cleaning, and IR inspection is followed to ensure a void free bonding. The wafer splitting was accomplished by annealing at the predetermined optimum condition, and high temperature annealing was then performed at $1,100^{\circ}C$ for 60 minutes to stabilize the bonding interface. TEM observation revealed no detectable defect at the SOI structure, and the interface trap charge density at the upper interface of the BOX was measured to be low enough to keep 'thermal' quality.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.4
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• pp.378-387
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• 1994

To improve the properties of $PbTiO_3$ thin films successfully grown by thermal diffusion of 3 component layers of $Ti0_2/Pb/TiO_2(900{\AA}/900{\AA}/900{\AA})$ in preceding research, 3, 5, 7, 9, and 11 multilayer structures $(TiO_2/Pb/.../Tio_2)$ with thinner component layer of $200~300 {\AA}$ thick were deposited on Si substrate by RF sputtering, which were followed by RTA to form $PbTiO_3$ thin films. As a result, $PbTiO_3$ single phase was formed above $500^{\circ}C$. When the thickness of component layer reduced and the number of component layers increased, suppression of Pb-silicate and voids formation resulted in relatively sharp interfaces and the film composition became more homogeneous. Relative dielectric constants in MIM structure were independent of the annealing condition, but they increased with increasing thickness of the $PbTiO_3$ thin films. The maximum breakdown field in MIS structure reached 150kV/cm.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.478-484
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• 2009

Three-dimensional porous scaffolds play an important role in tissue engineering strategies. They provide a void volume in which vascularization, new tissue formation, and remodeling can occur. Like any grafted materials, the ideal scaffold for bone tissue engineering should be biocompatible without causing an inflammatory response. It should also possess biodegradability, which provides a suitable three-dimensional environment for the cell function together with the capacity for gradual resorption and replacement by host bone tissue. Various scaffolds have already been developed for bone tissue engineering applications, including naturally derived materials, bioceramics, and synthetic polymers. The advantages of biodegradable synthetic polymers include the ability to tailor specific functions. The purpose of this study was to examine the osteogenic activity of periosteal-derived cells in a polydioxanone/pluronic F127 scaffold. Periosteal-derived cells were successfully differentiated into osteoblasts in the polydioxanone/pluronic F127 scaffold. ALP activity showed its peak level at 2 weeks of culture, followed by decreased activity during the culture period. Similar to biochemical data, the level of ALP mRNA in the periosteal-derived cells was also largely elevated at 2 weeks of culture. The level of osteocalcin mRNA was gradually increased during entire culture period. Calcium content was detactable at 1 week and increased in a time-dependent manner up to the entire duration of culture. Our results suggest that polydioxanone/pluronic F127 could be a suitable scaffold of periosteal-derived cells for bone tissue engineering.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.1-6
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• 2014

Flip chip bonded LED packages possess lower thermal resistance than wire bonded LED packages because of short thermal path. In this study, thermal and bonding properties of flip chip bonded high brightness LED were evaluated for Au-Sn thermo-compression bonded LEDs and Sn-Ag-Cu reflow bonded LEDs. For the Au-Sn thermo-compression bonding, bonding pressure and bonding temperature were 50 N and 300oC, respectively. For the SAC solder reflow bonding, peak temperature was $255^{\circ}C$ for 30 sec. The shear strength of the Au-Sn thermo-compression joint was $3508.5gf/mm^2$ and that of the SAC reflow joint was 5798.5 gf/mm. After the shear test, the fracture occurred at the isolation layer in the LED chip for both Au-Sn and SAC joints. Thermal resistance of Au-Sn sample was lower than that of SAC bonded sample due to the void formation in the SAC solder.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.37-45
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• 2008

In this study, reliabilities of Cu (60 um)/SnAg (20 um) double-bump flip chip assemblies were investigated for the flip chip interconnections on organic substrates with 100 um pitch. After multiple reflows at $250^{\circ}C\;and\;280^{\circ}C$, bump contact resistances were almost same regardless of number of reflows and reflow temperature. In the high temperature storage test, there was no bump contact resistance change at $125^{\circ}C$ up to 2000 hours. However, bump contact resistances slightly increased at $150^{\circ}C$ due to Kirkendall voids formation. In the electromigration test, Cu/SnAg double-bump flip chip assemblies showed no electromigration until about 600 hours due to reduced local current density. Finally, in the thermal cycling test, thermal cycling failure mainly occurred at Si chip/Cu column interface which was found out the highest stress concentration site in the finite element analysis. As a result, Al pad was displaced out under thermal cycling. This failure mode was caused by normal compressive strain acting Cu column bumps along perpendicular direction of a Si chip.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.557-567
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• 1995

The purpose of this study was to investigated the effect of root planing and decalcified freeze dried allografts on the resorption of transplanted roots and the healing of preveously diseased recipient extraction sockets. The experimental chronic periodontitis was induced by elastic ligatures on the 2nd and 3rd mandibular premolars of 4 adult dogs, and after 8 weeks, crowns were removed and the teeth extracted. The extracted roots were split in half along the long-axis, and the extednt of plaque exposure was morked on the root surfaces with burs. The roots were either root-planed(Test group), or left uninstrumented(Control group), and transplanted in the extraction sockets with decalcified freeze-dried allografts filling the void. The flaps were sutured to cover the sockets completely. The animals were sacrificed after 12 weeks of healing, and the specimens were examined histologically. The results were as follows : 1. No signs of inflammation or disease activity were observed in either groups. 2. Replacement root resorption was observed in both groups. 3. More connective tissue attachments and less ankylosis were observed in the test groups compared to the control. 4. The unresorbed remains of DFDB particles were observed in both groups. 5. DFDB particles in the apical portion of the alveolar sockets were encased in newly-formed bone, while those in the coronal areas were seen encapsulated with connective tissue. 6. No significant difference was found between root-planed and uninstrumented roots relative to the healing and the bone fromation in the recipient extraction sockdets. From the present study, there seemed to be no significant benefits in root planing the transplanted roots or grafting the sockets with DFDB in order to curve the replacement resorption, although the root-planed roots showed more connective tissue attachments. There was also no significant benefits in root transplantation and DFDB for and enhanced healing and bone formation in alveolar extraction sockets.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.14 no.2
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• pp.69-78
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• 1978

It is well known that the aluminizing steel is excellent in corrosion resistance and heat resistance. Therefore it has been used as boiler parts, heat exchanger parts and guide rails which are used under comparatively simple conditions. Recently, it has been noticed that aluminizing steel has high resistance to various atmosphere, high temperature oxidation and seawater resistance. So its usage has been extended widely to the production of parts such as intake and exhaust valve of internal combustion engine, turbine blade and pipelines On ships which required such properties. It is considered that aluminium coated steel is excellent in wear resistance because of high hardness on main ingredient FezAIs of Fe-AI alloy layer existed in diffusion coating layer. And it will beused as a new material taking wear resitance with seawater resistance in marine field. However it is difficult to findout any report concering the wear behaviors or properties of alum in izing steel. In this study the experiment was carried out under the condition of rolling-sliding contact using an Amsler-type wear testing machine at 0.80, 0.91, 1. 10, 1. 25% of slip ratio and 55.43, 78.38, 110.85 kg/mm^2 of Hertz's contact stress in run-in period for the purpose of service-ability test of aluminizing steel as a wear resisting material and obtaining the available design data. The followings are the obtained results from the experimen tal study; 1) The 2nd diffusion material has most excellent wear resistance. This material has brought out about 18% decrease of wear weight in a lower friction load level and 40~G decrease in a higher level comparing to the raw material. 2) Satisfactory effect of wear resistivity cannot be much expected in 2nd diffusion specimens. This is considered due to the formation of fine void in the alloy layer near the boundary to the aluminium layer. 3) Fracture on friction surface of aluminizing steel by the rolling-sliding contact is spalling, and spalling crack occurres initially beneath the specimen surface near the boundary in diffusion coating layer.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.77-77
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• 1998

Present silicon dioxide (SiOz) 떠m as intennetal dielectridIMD) layers will result in high parasitic c capacitance and crosstalk interference in 비gh density devices. Low dielectric materials such as f f1uorina뼈 silicon oxide(SiOF) and f1uoropolymer IMD layers have been tried to s이ve this problem. I In the SiOF ftlm, as fluorine concentration increases the dielectric constant of t뼈 film decreases but i it becomes unstable and wa않r absorptivity increases. The dielectric constant above 3.0 is obtain어 i in these ftlms. Fluoropolymers such as polyte$\sigma$따luoroethylene(PTFE) are known as low dielectric c constant (>2.0) materials. However, their $\alpha$)Or thermal stability and low adhesive fa$\pi$e have h hindered 야1리ru뚱 as IMD ma따"ials. 1 The concept of a plasma processing a찌Jaratus with 비gh density plasma at low pressure has r received much attention for deposition because films made in these plasma reactors have many a advantages such as go여 film quality and gap filling profile. High ion flux with low ion energy in m the high density plasma make the low contamination and go어 $\sigma$'Oss피lked ftlm. Especially the h helicon plasma reactor have attractive features for ftlm deposition 야~au똥 of i앙 high density plasma p production compared with other conventional type plasma soun:es. I In this pa야Jr, we present the results on the low dielectric constant fluorocarbonated-SiOF film d밑JOsited on p-Si(loo) 5 inch silicon substrates with 00% of 0dFTES gas mixture and 20% of Ar g gas in a helicon plasma reactor. High density 띠asma is generated in the conventional helicon p plasma soun:e with Nagoya type ill antenna, 5-15 MHz and 1 kW RF power, 700 Gauss of m magnetic field, and 1.5 mTorr of pressure. The electron density and temperature of the 0dFTES d discharge are measUI벼 by Langmuir probe. The relative density of radicals are measured by optic허 e emission spe따'Oscopy(OES). Chemical bonding structure 3I피 atomic concentration 따'C characterized u using fourier transform infrared(FTIR) s야3띠"Oscopy and X -ray photonelectron spl:’따'Oscopy (XPS). D Dielectric constant is measured using a metal insulator semiconductor (MIS;AVO.4 $\mu$ m thick f fIlmlp-SD s$\sigma$ucture. A chemical stoichiome$\sigma$y of 야Ie fluorocarbina$textsc{k}$영-SiOF film 따~si야영 at room temperature, which t the flow rate of Oz and FTES gas is Isccm and 6sccm, res야~tvely, is form려 야Ie SiouFo.36Co.14. A d dielec$\sigma$ic constant of this fIlm is 2.8, but the s$\alpha$'!Cimen at annealed 5OOt: is obtain려 3.24, and the s stepcoverage in the 0.4 $\mu$ m and 0.5 $\mu$ m pattern 킹'C above 92% and 91% without void, res야~tively. res야~tively.